diff --git a/bin/checkPad.js b/bin/checkPad.js
index 9e0544415..356b07799 100644
--- a/bin/checkPad.js
+++ b/bin/checkPad.js
@@ -15,7 +15,8 @@ var log4js = require("log4js");
 log4js.setGlobalLogLevel("INFO");
 var async = require("async");
 var db = require('../node/db/DB');
-var Changeset = require('../node/utils/Changeset');
+var CommonCode = require('../node/utils/common_code');
+var Changeset = CommonCode.require("/Changeset");
 var padManager;
 
 async.series([
diff --git a/bin/convert.js b/bin/convert.js
index 4302114c6..c5dc535cd 100644
--- a/bin/convert.js
+++ b/bin/convert.js
@@ -1,11 +1,12 @@
+var CommonCode = require('../node/utils/common_code');
 var startTime = new Date().getTime();
 var fs = require("fs");
 var ueberDB = require("ueberDB");
 var mysql = require("mysql");
 var async = require("async");
-var Changeset = require("../node/utils/Changeset");
-var randomString = require("../node/utils/randomstring");
-var AttributePoolFactory = require("../node/utils/AttributePoolFactory");
+var Changeset = CommonCode.require("/Changeset");
+var randomString = CommonCode.require('/pad_utils').randomString;
+var AttributePoolFactory = CommonCode.require("/AttributePoolFactory");
 
 var settingsFile = process.argv[2];
 var sqlOutputFile = process.argv[3];
diff --git a/node/db/AuthorManager.js b/node/db/AuthorManager.js
index 7c054a56f..9baf63475 100644
--- a/node/db/AuthorManager.js
+++ b/node/db/AuthorManager.js
@@ -18,11 +18,11 @@
  * limitations under the License.
  */
 
+var CommonCode = require('../utils/common_code');
 var ERR = require("async-stacktrace");
 var db = require("./DB").db;
 var async = require("async");
-
-var randomString = require("../utils/randomstring");
+var randomString = CommonCode.require('/pad_utils').randomString;
 
 /**
  * Checks if the author exists
diff --git a/node/db/GroupManager.js b/node/db/GroupManager.js
index 7e3b7d6d1..bd294ba62 100644
--- a/node/db/GroupManager.js
+++ b/node/db/GroupManager.js
@@ -18,9 +18,10 @@
  * limitations under the License.
  */
  
+var CommonCode = require('../utils/common_code');
 var ERR = require("async-stacktrace");
 var customError = require("../utils/customError");
-var randomString = require("../utils/randomstring");
+var randomString = CommonCode.require('/pad_utils').randomString;
 var db = require("./DB").db;
 var async = require("async");
 var padManager = require("./PadManager");
diff --git a/node/db/Pad.js b/node/db/Pad.js
index 632eebe8c..99a53143c 100644
--- a/node/db/Pad.js
+++ b/node/db/Pad.js
@@ -2,9 +2,11 @@
  * The pad object, defined with joose
  */
 
+var CommonCode = require('../utils/common_code');
 var ERR = require("async-stacktrace");
-var Changeset = require("../utils/Changeset");
-var AttributePoolFactory = require("../utils/AttributePoolFactory");
+var Changeset = CommonCode.require("/Changeset");
+var AttributePoolFactory = CommonCode.require("/AttributePoolFactory");
+var randomString = CommonCode.require('/pad_utils').randomString;
 var db = require("./DB").db;
 var async = require("async");
 var settings = require('../utils/Settings');
@@ -477,15 +479,7 @@ function hash(password, salt)
 
 function generateSalt()
 {
-  var len = 86;
-  var chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz./";
-  var randomstring = '';
-  for (var i = 0; i < len; i++)
-  {
-    var rnum = Math.floor(Math.random() * chars.length);
-    randomstring += chars.substring(rnum, rnum + 1);
-  }
-  return randomstring;
+  return randomstring(86);
 }
 
 function compare(hashStr, password)
diff --git a/node/db/ReadOnlyManager.js b/node/db/ReadOnlyManager.js
index 1e5079c52..e5dab99b4 100644
--- a/node/db/ReadOnlyManager.js
+++ b/node/db/ReadOnlyManager.js
@@ -18,11 +18,11 @@
  * limitations under the License.
  */
 
+var CommonCode = require('../utils/common_code');
 var ERR = require("async-stacktrace");
 var db = require("./DB").db;
 var async = require("async");
-
-var randomString = require("../utils/randomstring");
+var randomString = CommonCode.require('/pad_utils').randomString;
 
 /**
  * returns a read only id for a pad
diff --git a/node/db/SecurityManager.js b/node/db/SecurityManager.js
index 4b86d868a..33ab37d44 100644
--- a/node/db/SecurityManager.js
+++ b/node/db/SecurityManager.js
@@ -18,6 +18,7 @@
  * limitations under the License.
  */
 
+var CommonCode = require('../utils/common_code');
 var ERR = require("async-stacktrace");
 var db = require("./DB").db;
 var async = require("async");
@@ -25,8 +26,7 @@ var authorManager = require("./AuthorManager");
 var padManager = require("./PadManager");
 var sessionManager = require("./SessionManager");
 var settings = require("../utils/Settings")
-
-var randomString = require("../utils/randomstring");
+var randomString = CommonCode.require('/pad_utils').randomString;
 
 /**
  * This function controlls the access to a pad, it checks if the user can access a pad.
diff --git a/node/db/SessionManager.js b/node/db/SessionManager.js
index 084d4a695..c5af33c68 100644
--- a/node/db/SessionManager.js
+++ b/node/db/SessionManager.js
@@ -18,9 +18,10 @@
  * limitations under the License.
  */
  
+var CommonCode = require('../utils/common_code');
 var ERR = require("async-stacktrace");
 var customError = require("../utils/customError");
-var randomString = require("../utils/randomstring");
+var randomString = CommonCode.require('/pad_utils').randomString;
 var db = require("./DB").db;
 var async = require("async");
 var groupMangager = require("./GroupManager");
diff --git a/node/easysync_tests.js b/node/easysync_tests.js
index 5b73b7170..8e7398bea 100644
--- a/node/easysync_tests.js
+++ b/node/easysync_tests.js
@@ -20,8 +20,9 @@
  * limitations under the License.
  */
 
-var Changeset = require('./utils/Changeset');
-var AttributePoolFactory = require("./utils/AttributePoolFactory");
+var CommonCode = require('./utils/common_code');
+var Changeset = CommonCode.require("/Changeset");
+var AttributePoolFactory = CommonCode.require("/AttributePoolFactory");
 
 function random() {
   this.nextInt = function (maxValue) {
diff --git a/node/handler/APIHandler.js b/node/handler/APIHandler.js
index ca45e1f8f..a7f66151c 100644
--- a/node/handler/APIHandler.js
+++ b/node/handler/APIHandler.js
@@ -18,11 +18,12 @@
  * limitations under the License.
  */
 
+var CommonCode = require('../utils/common_code');
 var ERR = require("async-stacktrace");
 var fs = require("fs");
 var api = require("../db/API");
 var padManager = require("../db/PadManager");
-var randomString = require("../utils/randomstring");
+var randomString = CommonCode.require('/pad_utils').randomString;
 
 //ensure we have an apikey
 var apikey = null;
diff --git a/node/handler/PadMessageHandler.js b/node/handler/PadMessageHandler.js
index 4a078542c..19aa1f9b2 100644
--- a/node/handler/PadMessageHandler.js
+++ b/node/handler/PadMessageHandler.js
@@ -18,11 +18,12 @@
  * limitations under the License.
  */
 
+var CommonCode = require('../utils/common_code');
 var ERR = require("async-stacktrace");
 var async = require("async");
 var padManager = require("../db/PadManager");
-var Changeset = require("../utils/Changeset");
-var AttributePoolFactory = require("../utils/AttributePoolFactory");
+var Changeset = CommonCode.require("/Changeset");
+var AttributePoolFactory = CommonCode.require("/AttributePoolFactory");
 var authorManager = require("../db/AuthorManager");
 var readOnlyManager = require("../db/ReadOnlyManager");
 var settings = require('../utils/Settings');
diff --git a/node/handler/TimesliderMessageHandler.js b/node/handler/TimesliderMessageHandler.js
index b30a9fc9d..188068430 100644
--- a/node/handler/TimesliderMessageHandler.js
+++ b/node/handler/TimesliderMessageHandler.js
@@ -18,11 +18,12 @@
  * limitations under the License.
  */
 
+var CommonCode = require('../utils/common_code');
 var ERR = require("async-stacktrace");
 var async = require("async");
 var padManager = require("../db/PadManager");
-var Changeset = require("../utils/Changeset");
-var AttributePoolFactory = require("../utils/AttributePoolFactory");
+var Changeset = CommonCode.require("/Changeset");
+var AttributePoolFactory = CommonCode.require("/AttributePoolFactory");
 var settings = require('../utils/Settings');
 var authorManager = require("../db/AuthorManager");
 var log4js = require('log4js');
diff --git a/node/utils/ExportDokuWiki.js b/node/utils/ExportDokuWiki.js
index 48e4b2915..abe6d3471 100644
--- a/node/utils/ExportDokuWiki.js
+++ b/node/utils/ExportDokuWiki.js
@@ -15,7 +15,8 @@
  */
 
 var async = require("async");
-var Changeset = require("./Changeset");
+var CommonCode = require('./common_code');
+var Changeset = CommonCode.require("/Changeset");
 var padManager = require("../db/PadManager");
 
 function getPadDokuWiki(pad, revNum, callback)
diff --git a/node/utils/ExportHtml.js b/node/utils/ExportHtml.js
index d4be80d20..afeafd3a9 100644
--- a/node/utils/ExportHtml.js
+++ b/node/utils/ExportHtml.js
@@ -14,10 +14,12 @@
  * limitations under the License.
  */
 
+var CommonCode = require('./common_code');
 var async = require("async");
-var Changeset = require("./Changeset");
+var Changeset = CommonCode.require("/Changeset");
 var padManager = require("../db/PadManager");
 var ERR = require("async-stacktrace");
+var Security = CommonCode.require('/security');
 
 function getPadPlainText(pad, revNum)
 {
@@ -269,7 +271,7 @@ function getHTMLFromAtext(pad, atext)
         //from but they break the abiword parser and are completly useless
         s = s.replace(String.fromCharCode(12), "");
         
-        assem.append(_escapeHTML(s));
+        assem.append(_encodeWhitespace(Security.escapeHTML(s)));
       } // end iteration over spans in line
       
       var tags2close = [];
@@ -292,7 +294,7 @@ function getHTMLFromAtext(pad, atext)
         var url = urlData[1];
         var urlLength = url.length;
         processNextChars(startIndex - idx);
-        assem.append('<a href="' + _escapeHTML(url) + '">');
+        assem.append('<a href="' + Security.escapeHTMLAttribute(url) + '">');
         processNextChars(urlLength);
         assem.append('</a>');
       });
@@ -493,25 +495,7 @@ exports.getPadHTMLDocument = function (padId, revNum, noDocType, callback)
   });
 }
 
-function _escapeHTML(s)
-{
-  var re = /[&"<>]/g;
-  if (!re.MAP)
-  {
-    // persisted across function calls!
-    re.MAP = {
-      '&': '&amp;',
-      '"': '&quot;',
-      '<': '&lt;',
-      '>': '&gt;'
-    };
-  }
-  
-  s = s.replace(re, function (c)
-  {
-    return re.MAP[c];
-  });
-  
+function _encodeWhitespace(s) {
   return s.replace(/[^\x21-\x7E\s\t\n\r]/g, function(c)
   {
     return "&#" +c.charCodeAt(0) + ";"
diff --git a/node/utils/ImportHtml.js b/node/utils/ImportHtml.js
index 1b0bcaea7..ce8663697 100644
--- a/node/utils/ImportHtml.js
+++ b/node/utils/ImportHtml.js
@@ -17,9 +17,10 @@
 var jsdom = require('jsdom-nocontextifiy').jsdom;
 var log4js = require('log4js');
 
-var Changeset = require("./Changeset");
-var contentcollector = require("./contentcollector");
-var map = require("../../static/js/ace2_common.js").map;
+var CommonCode = require('../utils/common_code');
+var Changeset = CommonCode.require("/Changeset");
+var contentcollector = CommonCode.require("/contentcollector");
+var map = CommonCode.require("/ace2_common").map;
 
 function setPadHTML(pad, html, callback)
 {
diff --git a/node/utils/common_code.js b/node/utils/common_code.js
new file mode 100644
index 000000000..359c9cfec
--- /dev/null
+++ b/node/utils/common_code.js
@@ -0,0 +1,22 @@
+/**
+ * Copyright 2009 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS-IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+var RequireKernel = require('require-kernel/');
+
+var CLIENT_JS_SRC = __dirname + '/../../static/js/';
+var client_require = RequireKernel.requireForPaths('file://' + CLIENT_JS_SRC);
+
+exports.require = client_require;
diff --git a/node/utils/contentcollector.js b/node/utils/contentcollector.js
deleted file mode 100644
index a7fa940a6..000000000
--- a/node/utils/contentcollector.js
+++ /dev/null
@@ -1,692 +0,0 @@
-// THIS FILE IS ALSO AN APPJET MODULE: etherpad.collab.ace.contentcollector
-// %APPJET%: import("etherpad.collab.ace.easysync2.Changeset");
-// %APPJET%: import("etherpad.admin.plugins");
-/**
- * Copyright 2009 Google Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS-IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-var Changeset = require("../utils/Changeset");
-
-var _MAX_LIST_LEVEL = 8;
-
-function sanitizeUnicode(s)
-{
-  return s.replace(/[\uffff\ufffe\ufeff\ufdd0-\ufdef\ud800-\udfff]/g, '?');
-}
-
-function makeContentCollector(collectStyles, browser, apool, domInterface, className2Author)
-{
-  browser = browser || {};
-
-  var plugins_;
-  if (typeof(plugins) != 'undefined')
-  {
-    plugins_ = plugins;
-  }
-  else
-  {
-    plugins_ = {callHook: function () {}};
-  }
-
-  var dom = domInterface || {
-    isNodeText: function(n)
-    {
-      return (n.nodeType == 3);
-    },
-    nodeTagName: function(n)
-    {
-      return n.tagName;
-    },
-    nodeValue: function(n)
-    {
-      return n.nodeValue;
-    },
-    nodeNumChildren: function(n)
-    {
-      return n.childNodes.length;
-    },
-    nodeChild: function(n, i)
-    {
-      return n.childNodes.item(i);
-    },
-    nodeProp: function(n, p)
-    {
-      return n[p];
-    },
-    nodeAttr: function(n, a)
-    {
-      return n.getAttribute(a);
-    },
-    optNodeInnerHTML: function(n)
-    {
-      return n.innerHTML;
-    }
-  };
-
-  var _blockElems = {
-    "div": 1,
-    "p": 1,
-    "pre": 1,
-    "li": 1
-  };
-
-  function isBlockElement(n)
-  {
-    return !!_blockElems[(dom.nodeTagName(n) || "").toLowerCase()];
-  }
-
-  function textify(str)
-  {
-    return sanitizeUnicode(
-    str.replace(/[\n\r ]/g, ' ').replace(/\xa0/g, ' ').replace(/\t/g, '        '));
-  }
-
-  function getAssoc(node, name)
-  {
-    return dom.nodeProp(node, "_magicdom_" + name);
-  }
-
-  var lines = (function()
-  {
-    var textArray = [];
-    var attribsArray = [];
-    var attribsBuilder = null;
-    var op = Changeset.newOp('+');
-    var self = {
-      length: function()
-      {
-        return textArray.length;
-      },
-      atColumnZero: function()
-      {
-        return textArray[textArray.length - 1] === "";
-      },
-      startNew: function()
-      {
-        textArray.push("");
-        self.flush(true);
-        attribsBuilder = Changeset.smartOpAssembler();
-      },
-      textOfLine: function(i)
-      {
-        return textArray[i];
-      },
-      appendText: function(txt, attrString)
-      {
-        textArray[textArray.length - 1] += txt;
-        //dmesg(txt+" / "+attrString);
-        op.attribs = attrString;
-        op.chars = txt.length;
-        attribsBuilder.append(op);
-      },
-      textLines: function()
-      {
-        return textArray.slice();
-      },
-      attribLines: function()
-      {
-        return attribsArray;
-      },
-      // call flush only when you're done
-      flush: function(withNewline)
-      {
-        if (attribsBuilder)
-        {
-          attribsArray.push(attribsBuilder.toString());
-          attribsBuilder = null;
-        }
-      }
-    };
-    self.startNew();
-    return self;
-  }());
-  var cc = {};
-
-  function _ensureColumnZero(state)
-  {
-    if (!lines.atColumnZero())
-    {
-      cc.startNewLine(state);
-    }
-  }
-  var selection, startPoint, endPoint;
-  var selStart = [-1, -1],
-      selEnd = [-1, -1];
-  var blockElems = {
-    "div": 1,
-    "p": 1,
-    "pre": 1
-  };
-
-  function _isEmpty(node, state)
-  {
-    // consider clean blank lines pasted in IE to be empty
-    if (dom.nodeNumChildren(node) == 0) return true;
-    if (dom.nodeNumChildren(node) == 1 && getAssoc(node, "shouldBeEmpty") && dom.optNodeInnerHTML(node) == "&nbsp;" && !getAssoc(node, "unpasted"))
-    {
-      if (state)
-      {
-        var child = dom.nodeChild(node, 0);
-        _reachPoint(child, 0, state);
-        _reachPoint(child, 1, state);
-      }
-      return true;
-    }
-    return false;
-  }
-
-  function _pointHere(charsAfter, state)
-  {
-    var ln = lines.length() - 1;
-    var chr = lines.textOfLine(ln).length;
-    if (chr == 0 && state.listType && state.listType != 'none')
-    {
-      chr += 1; // listMarker
-    }
-    chr += charsAfter;
-    return [ln, chr];
-  }
-
-  function _reachBlockPoint(nd, idx, state)
-  {
-    if (!dom.isNodeText(nd)) _reachPoint(nd, idx, state);
-  }
-
-  function _reachPoint(nd, idx, state)
-  {
-    if (startPoint && nd == startPoint.node && startPoint.index == idx)
-    {
-      selStart = _pointHere(0, state);
-    }
-    if (endPoint && nd == endPoint.node && endPoint.index == idx)
-    {
-      selEnd = _pointHere(0, state);
-    }
-  }
-  cc.incrementFlag = function(state, flagName)
-  {
-    state.flags[flagName] = (state.flags[flagName] || 0) + 1;
-  }
-  cc.decrementFlag = function(state, flagName)
-  {
-    state.flags[flagName]--;
-  }
-  cc.incrementAttrib = function(state, attribName)
-  {
-    if (!state.attribs[attribName])
-    {
-      state.attribs[attribName] = 1;
-    }
-    else
-    {
-      state.attribs[attribName]++;
-    }
-    _recalcAttribString(state);
-  }
-  cc.decrementAttrib = function(state, attribName)
-  {
-    state.attribs[attribName]--;
-    _recalcAttribString(state);
-  }
-
-  function _enterList(state, listType)
-  {
-    var oldListType = state.listType;
-    state.listLevel = (state.listLevel || 0) + 1;
-    if (listType != 'none')
-    {
-      state.listNesting = (state.listNesting || 0) + 1;
-    }
-    state.listType = listType;
-    _recalcAttribString(state);
-    return oldListType;
-  }
-
-  function _exitList(state, oldListType)
-  {
-    state.listLevel--;
-    if (state.listType != 'none')
-    {
-      state.listNesting--;
-    }
-    state.listType = oldListType;
-    _recalcAttribString(state);
-  }
-
-  function _enterAuthor(state, author)
-  {
-    var oldAuthor = state.author;
-    state.authorLevel = (state.authorLevel || 0) + 1;
-    state.author = author;
-    _recalcAttribString(state);
-    return oldAuthor;
-  }
-
-  function _exitAuthor(state, oldAuthor)
-  {
-    state.authorLevel--;
-    state.author = oldAuthor;
-    _recalcAttribString(state);
-  }
-
-  function _recalcAttribString(state)
-  {
-    var lst = [];
-    for (var a in state.attribs)
-    {
-      if (state.attribs[a])
-      {
-        lst.push([a, 'true']);
-      }
-    }
-    if (state.authorLevel > 0)
-    {
-      var authorAttrib = ['author', state.author];
-      if (apool.putAttrib(authorAttrib, true) >= 0)
-      {
-        // require that author already be in pool
-        // (don't add authors from other documents, etc.)
-        lst.push(authorAttrib);
-      }
-    }
-    state.attribString = Changeset.makeAttribsString('+', lst, apool);
-  }
-
-  function _produceListMarker(state)
-  {
-    lines.appendText('*', Changeset.makeAttribsString('+', [
-      ['list', state.listType],
-      ['insertorder', 'first']
-    ], apool));
-  }
-  cc.startNewLine = function(state)
-  {
-    if (state)
-    {
-      var atBeginningOfLine = lines.textOfLine(lines.length() - 1).length == 0;
-      if (atBeginningOfLine && state.listType && state.listType != 'none')
-      {
-        _produceListMarker(state);
-      }
-    }
-    lines.startNew();
-  }
-  cc.notifySelection = function(sel)
-  {
-    if (sel)
-    {
-      selection = sel;
-      startPoint = selection.startPoint;
-      endPoint = selection.endPoint;
-    }
-  };
-  cc.doAttrib = function(state, na)
-  {
-    state.localAttribs = (state.localAttribs || []);
-    state.localAttribs.push(na);
-    cc.incrementAttrib(state, na);
-  };
-  cc.collectContent = function(node, state)
-  {
-    if (!state)
-    {
-      state = {
-        flags: { /*name -> nesting counter*/
-        },
-        localAttribs: null,
-        attribs: { /*name -> nesting counter*/
-        },
-        attribString: ''
-      };
-    }
-    var localAttribs = state.localAttribs;
-    state.localAttribs = null;
-    var isBlock = isBlockElement(node);
-    var isEmpty = _isEmpty(node, state);
-    if (isBlock) _ensureColumnZero(state);
-    var startLine = lines.length() - 1;
-    _reachBlockPoint(node, 0, state);
-    if (dom.isNodeText(node))
-    {
-      var txt = dom.nodeValue(node);
-      var rest = '';
-      var x = 0; // offset into original text
-      if (txt.length == 0)
-      {
-        if (startPoint && node == startPoint.node)
-        {
-          selStart = _pointHere(0, state);
-        }
-        if (endPoint && node == endPoint.node)
-        {
-          selEnd = _pointHere(0, state);
-        }
-      }
-      while (txt.length > 0)
-      {
-        var consumed = 0;
-        if (state.flags.preMode)
-        {
-          var firstLine = txt.split('\n', 1)[0];
-          consumed = firstLine.length + 1;
-          rest = txt.substring(consumed);
-          txt = firstLine;
-        }
-        else
-        { /* will only run this loop body once */
-        }
-        if (startPoint && node == startPoint.node && startPoint.index - x <= txt.length)
-        {
-          selStart = _pointHere(startPoint.index - x, state);
-        }
-        if (endPoint && node == endPoint.node && endPoint.index - x <= txt.length)
-        {
-          selEnd = _pointHere(endPoint.index - x, state);
-        }
-        var txt2 = txt;
-        if ((!state.flags.preMode) && /^[\r\n]*$/.exec(txt))
-        {
-          // prevents textnodes containing just "\n" from being significant
-          // in safari when pasting text, now that we convert them to
-          // spaces instead of removing them, because in other cases
-          // removing "\n" from pasted HTML will collapse words together.
-          txt2 = "";
-        }
-        var atBeginningOfLine = lines.textOfLine(lines.length() - 1).length == 0;
-        if (atBeginningOfLine)
-        {
-          // newlines in the source mustn't become spaces at beginning of line box
-          txt2 = txt2.replace(/^\n*/, '');
-        }
-        if (atBeginningOfLine && state.listType && state.listType != 'none')
-        {
-          _produceListMarker(state);
-        }
-        lines.appendText(textify(txt2), state.attribString);
-        x += consumed;
-        txt = rest;
-        if (txt.length > 0)
-        {
-          cc.startNewLine(state);
-        }
-      }
-    }
-    else
-    {
-      var tname = (dom.nodeTagName(node) || "").toLowerCase();
-      if (tname == "br")
-      {
-        cc.startNewLine(state);
-      }
-      else if (tname == "script" || tname == "style")
-      {
-        // ignore
-      }
-      else if (!isEmpty)
-      {
-        var styl = dom.nodeAttr(node, "style");
-        var cls = dom.nodeProp(node, "className");
-
-        var isPre = (tname == "pre");
-        if ((!isPre) && browser.safari)
-        {
-          isPre = (styl && /\bwhite-space:\s*pre\b/i.exec(styl));
-        }
-        if (isPre) cc.incrementFlag(state, 'preMode');
-        var oldListTypeOrNull = null;
-        var oldAuthorOrNull = null;
-        if (collectStyles)
-        {
-          plugins_.callHook('collectContentPre', {
-            cc: cc,
-            state: state,
-            tname: tname,
-            styl: styl,
-            cls: cls
-          });
-          if (tname == "b" || (styl && /\bfont-weight:\s*bold\b/i.exec(styl)) || tname == "strong")
-          {
-            cc.doAttrib(state, "bold");
-          }
-          if (tname == "i" || (styl && /\bfont-style:\s*italic\b/i.exec(styl)) || tname == "em")
-          {
-            cc.doAttrib(state, "italic");
-          }
-          if (tname == "u" || (styl && /\btext-decoration:\s*underline\b/i.exec(styl)) || tname == "ins")
-          {
-            cc.doAttrib(state, "underline");
-          }
-          if (tname == "s" || (styl && /\btext-decoration:\s*line-through\b/i.exec(styl)) || tname == "del")
-          {
-            cc.doAttrib(state, "strikethrough");
-          }
-          if (tname == "ul" || tname == "ol")
-          {
-            var type;
-            var rr = cls && /(?:^| )list-([a-z]+[12345678])\b/.exec(cls);
-            type = rr && rr[1] || "bullet" + String(Math.min(_MAX_LIST_LEVEL, (state.listNesting || 0) + 1));
-            oldListTypeOrNull = (_enterList(state, type) || 'none');
-          }
-          else if ((tname == "div" || tname == "p") && cls && cls.match(/(?:^| )ace-line\b/))
-          {
-            oldListTypeOrNull = (_enterList(state, type) || 'none');
-          }
-          if (className2Author && cls)
-          {
-            var classes = cls.match(/\S+/g);
-            if (classes && classes.length > 0)
-            {
-              for (var i = 0; i < classes.length; i++)
-              {
-                var c = classes[i];
-                var a = className2Author(c);
-                if (a)
-                {
-                  oldAuthorOrNull = (_enterAuthor(state, a) || 'none');
-                  break;
-                }
-              }
-            }
-          }
-        }
-
-        var nc = dom.nodeNumChildren(node);
-        for (var i = 0; i < nc; i++)
-        {
-          var c = dom.nodeChild(node, i);
-          cc.collectContent(c, state);
-        }
-
-        if (collectStyles)
-        {
-          plugins_.callHook('collectContentPost', {
-            cc: cc,
-            state: state,
-            tname: tname,
-            styl: styl,
-            cls: cls
-          });
-        }
-
-        if (isPre) cc.decrementFlag(state, 'preMode');
-        if (state.localAttribs)
-        {
-          for (var i = 0; i < state.localAttribs.length; i++)
-          {
-            cc.decrementAttrib(state, state.localAttribs[i]);
-          }
-        }
-        if (oldListTypeOrNull)
-        {
-          _exitList(state, oldListTypeOrNull);
-        }
-        if (oldAuthorOrNull)
-        {
-          _exitAuthor(state, oldAuthorOrNull);
-        }
-      }
-    }
-    if (!browser.msie)
-    {
-      _reachBlockPoint(node, 1, state);
-    }
-    if (isBlock)
-    {
-      if (lines.length() - 1 == startLine)
-      {
-        cc.startNewLine(state);
-      }
-      else
-      {
-        _ensureColumnZero(state);
-      }
-    }
-
-    if (browser.msie)
-    {
-      // in IE, a point immediately after a DIV appears on the next line
-      _reachBlockPoint(node, 1, state);
-    }
-
-    state.localAttribs = localAttribs;
-  };
-  // can pass a falsy value for end of doc
-  cc.notifyNextNode = function(node)
-  {
-    // an "empty block" won't end a line; this addresses an issue in IE with
-    // typing into a blank line at the end of the document.  typed text
-    // goes into the body, and the empty line div still looks clean.
-    // it is incorporated as dirty by the rule that a dirty region has
-    // to end a line.
-    if ((!node) || (isBlockElement(node) && !_isEmpty(node)))
-    {
-      _ensureColumnZero(null);
-    }
-  };
-  // each returns [line, char] or [-1,-1]
-  var getSelectionStart = function()
-    {
-      return selStart;
-      };
-  var getSelectionEnd = function()
-    {
-      return selEnd;
-      };
-
-  // returns array of strings for lines found, last entry will be "" if
-  // last line is complete (i.e. if a following span should be on a new line).
-  // can be called at any point
-  cc.getLines = function()
-  {
-    return lines.textLines();
-  };
-
-  cc.finish = function()
-  {
-    lines.flush();
-    var lineAttribs = lines.attribLines();
-    var lineStrings = cc.getLines();
-
-    lineStrings.length--;
-    lineAttribs.length--;
-
-    var ss = getSelectionStart();
-    var se = getSelectionEnd();
-
-    function fixLongLines()
-    {
-      // design mode does not deal with with really long lines!
-      var lineLimit = 2000; // chars
-      var buffer = 10; // chars allowed over before wrapping
-      var linesWrapped = 0;
-      var numLinesAfter = 0;
-      for (var i = lineStrings.length - 1; i >= 0; i--)
-      {
-        var oldString = lineStrings[i];
-        var oldAttribString = lineAttribs[i];
-        if (oldString.length > lineLimit + buffer)
-        {
-          var newStrings = [];
-          var newAttribStrings = [];
-          while (oldString.length > lineLimit)
-          {
-            //var semiloc = oldString.lastIndexOf(';', lineLimit-1);
-            //var lengthToTake = (semiloc >= 0 ? (semiloc+1) : lineLimit);
-            lengthToTake = lineLimit;
-            newStrings.push(oldString.substring(0, lengthToTake));
-            oldString = oldString.substring(lengthToTake);
-            newAttribStrings.push(Changeset.subattribution(oldAttribString, 0, lengthToTake));
-            oldAttribString = Changeset.subattribution(oldAttribString, lengthToTake);
-          }
-          if (oldString.length > 0)
-          {
-            newStrings.push(oldString);
-            newAttribStrings.push(oldAttribString);
-          }
-
-          function fixLineNumber(lineChar)
-          {
-            if (lineChar[0] < 0) return;
-            var n = lineChar[0];
-            var c = lineChar[1];
-            if (n > i)
-            {
-              n += (newStrings.length - 1);
-            }
-            else if (n == i)
-            {
-              var a = 0;
-              while (c > newStrings[a].length)
-              {
-                c -= newStrings[a].length;
-                a++;
-              }
-              n += a;
-            }
-            lineChar[0] = n;
-            lineChar[1] = c;
-          }
-          fixLineNumber(ss);
-          fixLineNumber(se);
-          linesWrapped++;
-          numLinesAfter += newStrings.length;
-
-          newStrings.unshift(i, 1);
-          lineStrings.splice.apply(lineStrings, newStrings);
-          newAttribStrings.unshift(i, 1);
-          lineAttribs.splice.apply(lineAttribs, newAttribStrings);
-        }
-      }
-      return {
-        linesWrapped: linesWrapped,
-        numLinesAfter: numLinesAfter
-      };
-    }
-    var wrapData = fixLongLines();
-
-    return {
-      selStart: ss,
-      selEnd: se,
-      linesWrapped: wrapData.linesWrapped,
-      numLinesAfter: wrapData.numLinesAfter,
-      lines: lineStrings,
-      lineAttribs: lineAttribs
-    };
-  }
-
-  return cc;
-}
-
-exports.makeContentCollector = makeContentCollector;
diff --git a/node/utils/randomstring.js b/node/utils/randomstring.js
deleted file mode 100644
index 4c1bba244..000000000
--- a/node/utils/randomstring.js
+++ /dev/null
@@ -1,16 +0,0 @@
-/**
- * Generates a random String with the given length. Is needed to generate the Author, Group, readonly, session Ids
- */
-var randomString = function randomString(len)
-{
-  var chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
-  var randomstring = '';
-  for (var i = 0; i < len; i++)
-  {
-    var rnum = Math.floor(Math.random() * chars.length);
-    randomstring += chars.substring(rnum, rnum + 1);
-  }
-  return randomstring;
-};
-
-module.exports = randomString;
diff --git a/node/utils/tar.json b/node/utils/tar.json
index b319791cf..e922dddeb 100644
--- a/node/utils/tar.json
+++ b/node/utils/tar.json
@@ -1,6 +1,7 @@
 {
   "pad.js": [
     "jquery.js"
+  , "security.js"
   , "pad.js"
   , "ace2_common.js"
   , "pad_utils.js"
@@ -25,6 +26,7 @@
   ]
 , "timeslider.js": [
     "jquery.js"
+  , "security.js"
   , "plugins.js"
   , "undo-xpopup.js"
   , "json2.js"
@@ -39,10 +41,11 @@
   , "pad_modals.js"
   , "pad_savedrevs.js"
   , "pad_impexp.js"
-  , "easysync2_client.js"
-  , "domline_client.js"
-  , "linestylefilter_client.js"
-  , "cssmanager_client.js"
+  , "AttributePoolFactory.js"
+  , "Changeset.js"
+  , "domline.js"
+  , "linestylefilter.js"
+  , "cssmanager.js"
   , "broadcast.js"
   , "broadcast_slider.js"
   , "broadcast_revisions.js"
@@ -50,9 +53,11 @@
   ]
 , "ace2_inner.js": [
     "ace2_common.js"
+  , "AttributePoolFactory.js"
+  , "Changeset.js"
+  , "security.js"
   , "skiplist.js"
   , "virtual_lines.js"
-  , "easysync2.js"
   , "cssmanager.js"
   , "colorutils.js"
   , "undomodule.js"
diff --git a/node/utils/AttributePoolFactory.js b/static/js/AttributePoolFactory.js
similarity index 97%
rename from node/utils/AttributePoolFactory.js
rename to static/js/AttributePoolFactory.js
index 807c2b393..00b58dbb3 100644
--- a/node/utils/AttributePoolFactory.js
+++ b/static/js/AttributePoolFactory.js
@@ -1,8 +1,8 @@
 /**
- * This code represents the Attribute Pool Object of the original Etherpad. 
+ * This code represents the Attribute Pool Object of the original Etherpad.
  * 90% of the code is still like in the original Etherpad
  * Look at https://github.com/ether/pad/blob/master/infrastructure/ace/www/easysync2.js
- * You can find a explanation what a attribute pool is here: 
+ * You can find a explanation what a attribute pool is here:
  * https://github.com/Pita/etherpad-lite/blob/master/doc/easysync/easysync-notes.txt
  */
 
diff --git a/node/utils/Changeset.js b/static/js/Changeset.js
similarity index 99%
rename from node/utils/Changeset.js
rename to static/js/Changeset.js
index 9e1b60ebe..715836d5f 100644
--- a/node/utils/Changeset.js
+++ b/static/js/Changeset.js
@@ -1,10 +1,10 @@
 /*
  * This is the Changeset library copied from the old Etherpad with some modifications to use it in node.js
  * Can be found in https://github.com/ether/pad/blob/master/infrastructure/ace/www/easysync2.js
- */ 
+ */
 
 /**
- * This code is mostly from the old Etherpad. Please help us to comment this code. 
+ * This code is mostly from the old Etherpad. Please help us to comment this code.
  * This helps other people to understand this code better and helps them to improve it.
  * TL;DR COMMENTS ON THIS FILE ARE HIGHLY APPRECIATED
  */
@@ -25,7 +25,7 @@
  * limitations under the License.
  */
 
-var AttributePoolFactory = require("./AttributePoolFactory");
+var AttributePoolFactory = require("/AttributePoolFactory");
 
 var _opt = null;
 
diff --git a/static/js/ace2_common.js b/static/js/ace2_common.js
index 1ce7810aa..b4c72a92f 100644
--- a/static/js/ace2_common.js
+++ b/static/js/ace2_common.js
@@ -20,6 +20,7 @@
  * limitations under the License.
  */
 
+var Security = require('/security');
 
 function isNodeText(node)
 {
@@ -137,14 +138,7 @@ function binarySearchInfinite(expectedLength, func)
 
 function htmlPrettyEscape(str)
 {
-  return str.replace(/[&"<>]/g, function (c) {
-    return {
-      '&': '&amp;',
-      '"': '&quot;',
-      '<': '&lt;',
-      '>': '&gt;'
-    }[c] || c;
-  }).replace(/\r?\n/g, '\\n');
+  return Security.escapeHTML(str).replace(/\r?\n/g, '\\n');
 }
 
 exports.isNodeText = isNodeText;
diff --git a/static/js/ace2_inner.js b/static/js/ace2_inner.js
index 31d4dac94..d21135743 100644
--- a/static/js/ace2_inner.js
+++ b/static/js/ace2_inner.js
@@ -42,8 +42,8 @@ var colorutils = require('/colorutils').colorutils;
 var makeContentCollector = require('/contentcollector').makeContentCollector;
 var makeCSSManager = require('/cssmanager').makeCSSManager;
 var domline = require('/domline').domline;
-var AttribPool = require('/easysync2').AttribPool;
-var Changeset = require('/easysync2').Changeset;
+var AttribPool = require('/AttributePoolFactory').createAttributePool;
+var Changeset = require('/Changeset');
 var linestylefilter = require('/linestylefilter').linestylefilter;
 var newSkipList = require('/skiplist').newSkipList;
 var undoModule = require('/undomodule').undoModule;
diff --git a/static/js/broadcast.js b/static/js/broadcast.js
index 020f47e7c..4a7b01681 100644
--- a/static/js/broadcast.js
+++ b/static/js/broadcast.js
@@ -20,11 +20,11 @@
  * limitations under the License.
  */
 
-var makeCSSManager = require('/cssmanager_client').makeCSSManager;
-var domline = require('/domline_client').domline;
-var Changeset = require('/easysync2_client').Changeset;
-var AttribPool = require('/easysync2_client').AttribPool;
-var linestylefilter = require('/linestylefilter_client').linestylefilter;
+var makeCSSManager = require('/cssmanager').makeCSSManager;
+var domline = require('/domline').domline;
+var AttribPool = require('/AttributePoolFactory').createAttributePool;
+var Changeset = require('/Changeset');
+var linestylefilter = require('/linestylefilter').linestylefilter;
 var colorutils = require('/colorutils').colorutils;
 
 // These parameters were global, now they are injected. A reference to the
diff --git a/static/js/changesettracker.js b/static/js/changesettracker.js
index 7b0fb3e46..e34dc107e 100644
--- a/static/js/changesettracker.js
+++ b/static/js/changesettracker.js
@@ -20,8 +20,8 @@
  * limitations under the License.
  */
 
-var Changeset = require('/easysync2').Changeset;
-var AttribPool = require('/easysync2').AttribPool;
+var AttribPool = require('/AttributePoolFactory').createAttributePool;
+var Changeset = require('/Changeset');
 
 function makeChangesetTracker(scheduler, apool, aceCallbacksProvider)
 {
diff --git a/static/js/contentcollector.js b/static/js/contentcollector.js
index 0437ccd7b..96dc4b7dd 100644
--- a/static/js/contentcollector.js
+++ b/static/js/contentcollector.js
@@ -25,7 +25,7 @@
 
 var _MAX_LIST_LEVEL = 8;
 
-var Changeset = require('/easysync2').Changeset
+var Changeset = require('/Changeset');
 var plugins = require('/plugins').plugins;
 
 function sanitizeUnicode(s)
diff --git a/static/js/cssmanager_client.js b/static/js/cssmanager_client.js
deleted file mode 100644
index 6d9d989e8..000000000
--- a/static/js/cssmanager_client.js
+++ /dev/null
@@ -1,118 +0,0 @@
-/**
- * This code is mostly from the old Etherpad. Please help us to comment this code. 
- * This helps other people to understand this code better and helps them to improve it.
- * TL;DR COMMENTS ON THIS FILE ARE HIGHLY APPRECIATED
- */
-
-// DO NOT EDIT THIS FILE, edit infrastructure/ace/www/cssmanager.js
-/**
- * Copyright 2009 Google Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS-IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-function makeCSSManager(emptyStylesheetTitle)
-{
-
-  function getSheetByTitle(title)
-  {
-    var allSheets = document.styleSheets;
-    for (var i = 0; i < allSheets.length; i++)
-    {
-      var s = allSheets[i];
-      if (s.title == title)
-      {
-        return s;
-      }
-    }
-    return null;
-  }
-
-/*function getSheetTagByTitle(title) {
-    var allStyleTags = document.getElementsByTagName("style");
-    for(var i=0;i<allStyleTags.length;i++) {
-      var t = allStyleTags[i];
-      if (t.title == title) {
-	return t;
-      }
-    }
-    return null;
-  }*/
-
-  var browserSheet = getSheetByTitle(emptyStylesheetTitle);
-  //var browserTag = getSheetTagByTitle(emptyStylesheetTitle);
-
-  function browserRules()
-  {
-    return (browserSheet.cssRules || browserSheet.rules);
-  }
-
-  function browserDeleteRule(i)
-  {
-    if (browserSheet.deleteRule) browserSheet.deleteRule(i);
-    else browserSheet.removeRule(i);
-  }
-
-  function browserInsertRule(i, selector)
-  {
-    if (browserSheet.insertRule) browserSheet.insertRule(selector + ' {}', i);
-    else browserSheet.addRule(selector, null, i);
-  }
-  var selectorList = [];
-
-  function indexOfSelector(selector)
-  {
-    for (var i = 0; i < selectorList.length; i++)
-    {
-      if (selectorList[i] == selector)
-      {
-        return i;
-      }
-    }
-    return -1;
-  }
-
-  function selectorStyle(selector)
-  {
-    var i = indexOfSelector(selector);
-    if (i < 0)
-    {
-      // add selector
-      browserInsertRule(0, selector);
-      selectorList.splice(0, 0, selector);
-      i = 0;
-    }
-    return browserRules().item(i).style;
-  }
-
-  function removeSelectorStyle(selector)
-  {
-    var i = indexOfSelector(selector);
-    if (i >= 0)
-    {
-      browserDeleteRule(i);
-      selectorList.splice(i, 1);
-    }
-  }
-
-  return {
-    selectorStyle: selectorStyle,
-    removeSelectorStyle: removeSelectorStyle,
-    info: function()
-    {
-      return selectorList.length + ":" + browserRules().length;
-    }
-  };
-}
-
-exports.makeCSSManager = makeCSSManager;
diff --git a/static/js/domline.js b/static/js/domline.js
index 8d8c2ea9e..15528bf7a 100644
--- a/static/js/domline.js
+++ b/static/js/domline.js
@@ -26,6 +26,7 @@
 // requires: plugins
 // requires: undefined
 
+var Security = require('/security');
 var plugins = require('/plugins').plugins;
 var map = require('/ace2_common').map;
 
@@ -103,17 +104,17 @@ domline.createDomLine = function(nonEmpty, doesWrap, optBrowser, optDocument)
       if (listType)
       {
         listType = listType[1];
-        start = start?'start="'+start[1]+'"':'';
+        start = start?'start="'+Security.escapeHTMLAttribute(start[1])+'"':'';
         if (listType)
         {
           if(listType.indexOf("number") < 0)
           {
-            preHtml = '<ul class="list-' + listType + '"><li>';
+            preHtml = '<ul class="list-' + Security.escapeHTMLAttribute(listType) + '"><li>';
             postHtml = '</li></ul>';
           }
           else
           {
-            preHtml = '<ol '+start+' class="list-' + listType + '"><li>';
+            preHtml = '<ol '+start+' class="list-' + Security.escapeHTMLAttribute(listType) + '"><li>';
             postHtml = '</li></ol>';
           }
         }
@@ -168,7 +169,7 @@ domline.createDomLine = function(nonEmpty, doesWrap, optBrowser, optDocument)
         {
           href = "http://"+href;
         }
-        extraOpenTags = extraOpenTags + '<a href="' + domline.escapeHTML(href) + '">';
+        extraOpenTags = extraOpenTags + '<a href="' + Security.escapeHTMLAttribute(href) + '">';
         extraCloseTags = '</a>' + extraCloseTags;
       }
       if (simpleTags)
@@ -178,7 +179,7 @@ domline.createDomLine = function(nonEmpty, doesWrap, optBrowser, optDocument)
         simpleTags.reverse();
         extraCloseTags = '</' + simpleTags.join('></') + '>' + extraCloseTags;
       }
-      html.push('<span class="', cls || '', '">', extraOpenTags, perTextNodeProcess(domline.escapeHTML(txt)), extraCloseTags, '</span>');
+      html.push('<span class="', Security.escapeHTMLAttribute(cls || ''), '">', extraOpenTags, perTextNodeProcess(Security.escapeHTML(txt)), extraCloseTags, '</span>');
     }
   };
   result.clearSpans = function()
@@ -224,27 +225,6 @@ domline.createDomLine = function(nonEmpty, doesWrap, optBrowser, optDocument)
   return result;
 };
 
-domline.escapeHTML = function(s)
-{
-  var re = /[&<>'"]/g;
-  /']/; // stupid indentation thing
-  if (!re.MAP)
-  {
-    // persisted across function calls!
-    re.MAP = {
-      '&': '&amp;',
-      '<': '&lt;',
-      '>': '&gt;',
-      '"': '&quot;',
-      "'": '&#39;'
-    };
-  }
-  return s.replace(re, function(c)
-  {
-    return re.MAP[c];
-  });
-};
-
 domline.processSpaces = function(s, doesWrap)
 {
   if (s.indexOf("<") < 0 && !doesWrap)
diff --git a/static/js/domline_client.js b/static/js/domline_client.js
deleted file mode 100644
index 87b6ed558..000000000
--- a/static/js/domline_client.js
+++ /dev/null
@@ -1,309 +0,0 @@
-/**
- * This code is mostly from the old Etherpad. Please help us to comment this code. 
- * This helps other people to understand this code better and helps them to improve it.
- * TL;DR COMMENTS ON THIS FILE ARE HIGHLY APPRECIATED
- */
-
-// DO NOT EDIT THIS FILE, edit infrastructure/ace/www/domline.js
-// THIS FILE IS ALSO AN APPJET MODULE: etherpad.collab.ace.domline
-/**
- * Copyright 2009 Google Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS-IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-// requires: top
-// requires: plugins
-// requires: undefined
-
-var plugins = require('/plugins').plugins;
-var map = require('/ace2_common').map;
-
-var domline = {};
-domline.noop = function()
-{};
-domline.identity = function(x)
-{
-  return x;
-};
-
-domline.addToLineClass = function(lineClass, cls)
-{
-  // an "empty span" at any point can be used to add classes to
-  // the line, using line:className.  otherwise, we ignore
-  // the span.
-  cls.replace(/\S+/g, function(c)
-  {
-    if (c.indexOf("line:") == 0)
-    {
-      // add class to line
-      lineClass = (lineClass ? lineClass + ' ' : '') + c.substring(5);
-    }
-  });
-  return lineClass;
-}
-
-// if "document" is falsy we don't create a DOM node, just
-// an object with innerHTML and className
-domline.createDomLine = function(nonEmpty, doesWrap, optBrowser, optDocument)
-{
-  var result = {
-    node: null,
-    appendSpan: domline.noop,
-    prepareForAdd: domline.noop,
-    notifyAdded: domline.noop,
-    clearSpans: domline.noop,
-    finishUpdate: domline.noop,
-    lineMarker: 0
-  };
-
-  var browser = (optBrowser || {});
-  var document = optDocument;
-
-  if (document)
-  {
-    result.node = document.createElement("div");
-  }
-  else
-  {
-    result.node = {
-      innerHTML: '',
-      className: ''
-    };
-  }
-
-  var html = [];
-  var preHtml, postHtml;
-  var curHTML = null;
-
-  function processSpaces(s)
-  {
-    return domline.processSpaces(s, doesWrap);
-  }
-  var identity = domline.identity;
-  var perTextNodeProcess = (doesWrap ? identity : processSpaces);
-  var perHtmlLineProcess = (doesWrap ? processSpaces : identity);
-  var lineClass = 'ace-line';
-  result.appendSpan = function(txt, cls)
-  {
-    if (cls.indexOf('list') >= 0)
-    {
-      var listType = /(?:^| )list:(\S+)/.exec(cls);
-      var start = /(?:^| )start:(\S+)/.exec(cls);
-      if (listType)
-      {
-        listType = listType[1];
-        start = start?'start="'+start[1]+'"':'';
-        if (listType)
-        {
-          if(listType.indexOf("number") < 0)
-          {
-            preHtml = '<ul class="list-' + listType + '"><li>';
-            postHtml = '</li></ul>';
-          }
-          else
-          {
-            preHtml = '<ol '+start+' class="list-' + listType + '"><li>';
-            postHtml = '</li></ol>';
-          }
-        }
-        result.lineMarker += txt.length;
-        return; // don't append any text
-      }
-    }
-    var href = null;
-    var simpleTags = null;
-    if (cls.indexOf('url') >= 0)
-    {
-      cls = cls.replace(/(^| )url:(\S+)/g, function(x0, space, url)
-      {
-        href = url;
-        return space + "url";
-      });
-    }
-    if (cls.indexOf('tag') >= 0)
-    {
-      cls = cls.replace(/(^| )tag:(\S+)/g, function(x0, space, tag)
-      {
-        if (!simpleTags) simpleTags = [];
-        simpleTags.push(tag.toLowerCase());
-        return space + tag;
-      });
-    }
-
-    var extraOpenTags = "";
-    var extraCloseTags = "";
-
-    var plugins_ = plugins;
-
-    map(plugins_.callHook("aceCreateDomLine", {
-      domline: domline,
-      cls: cls
-    }), function(modifier)
-    {
-      cls = modifier.cls;
-      extraOpenTags = extraOpenTags + modifier.extraOpenTags;
-      extraCloseTags = modifier.extraCloseTags + extraCloseTags;
-    });
-
-    if ((!txt) && cls)
-    {
-      lineClass = domline.addToLineClass(lineClass, cls);
-    }
-    else if (txt)
-    {
-      if (href)
-      {
-        if(!~href.indexOf("http")) // if the url doesn't include http or https etc prefix it.
-        {
-          href = "http://"+href;
-        }
-        extraOpenTags = extraOpenTags + '<a href="' + href.replace(/\"/g, '&quot;') + '">';
-        extraCloseTags = '</a>' + extraCloseTags;
-      }
-      if (simpleTags)
-      {
-        simpleTags.sort();
-        extraOpenTags = extraOpenTags + '<' + simpleTags.join('><') + '>';
-        simpleTags.reverse();
-        extraCloseTags = '</' + simpleTags.join('></') + '>' + extraCloseTags;
-      }
-      html.push('<span class="', cls || '', '">', extraOpenTags, perTextNodeProcess(domline.escapeHTML(txt)), extraCloseTags, '</span>');
-    }
-  };
-  result.clearSpans = function()
-  {
-    html = [];
-    lineClass = ''; // non-null to cause update
-    result.lineMarker = 0;
-  };
-
-  function writeHTML()
-  {
-    var newHTML = perHtmlLineProcess(html.join(''));
-    if (!newHTML)
-    {
-      if ((!document) || (!optBrowser))
-      {
-        newHTML += '&nbsp;';
-      }
-      else if (!browser.msie)
-      {
-        newHTML += '<br/>';
-      }
-    }
-    if (nonEmpty)
-    {
-      newHTML = (preHtml || '') + newHTML + (postHtml || '');
-    }
-    html = preHtml = postHtml = null; // free memory
-    if (newHTML !== curHTML)
-    {
-      curHTML = newHTML;
-      result.node.innerHTML = curHTML;
-    }
-    if (lineClass !== null) result.node.className = lineClass;
-  }
-  result.prepareForAdd = writeHTML;
-  result.finishUpdate = writeHTML;
-  result.getInnerHTML = function()
-  {
-    return curHTML || '';
-  };
-
-  return result;
-};
-
-domline.escapeHTML = function(s)
-{
-  var re = /[&<>'"]/g;
-  /']/; // stupid indentation thing
-  if (!re.MAP)
-  {
-    // persisted across function calls!
-    re.MAP = {
-      '&': '&amp;',
-      '<': '&lt;',
-      '>': '&gt;',
-      '"': '&#34;',
-      "'": '&#39;'
-    };
-  }
-  return s.replace(re, function(c)
-  {
-    return re.MAP[c];
-  });
-};
-
-domline.processSpaces = function(s, doesWrap)
-{
-  if (s.indexOf("<") < 0 && !doesWrap)
-  {
-    // short-cut
-    return s.replace(/ /g, '&nbsp;');
-  }
-  var parts = [];
-  s.replace(/<[^>]*>?| |[^ <]+/g, function(m)
-  {
-    parts.push(m);
-  });
-  if (doesWrap)
-  {
-    var endOfLine = true;
-    var beforeSpace = false;
-    // last space in a run is normal, others are nbsp,
-    // end of line is nbsp
-    for (var i = parts.length - 1; i >= 0; i--)
-    {
-      var p = parts[i];
-      if (p == " ")
-      {
-        if (endOfLine || beforeSpace) parts[i] = '&nbsp;';
-        endOfLine = false;
-        beforeSpace = true;
-      }
-      else if (p.charAt(0) != "<")
-      {
-        endOfLine = false;
-        beforeSpace = false;
-      }
-    }
-    // beginning of line is nbsp
-    for (var i = 0; i < parts.length; i++)
-    {
-      var p = parts[i];
-      if (p == " ")
-      {
-        parts[i] = '&nbsp;';
-        break;
-      }
-      else if (p.charAt(0) != "<")
-      {
-        break;
-      }
-    }
-  }
-  else
-  {
-    for (var i = 0; i < parts.length; i++)
-    {
-      var p = parts[i];
-      if (p == " ")
-      {
-        parts[i] = '&nbsp;';
-      }
-    }
-  }
-  return parts.join('');
-};
-
-exports.domline = domline;
diff --git a/static/js/easysync2.js b/static/js/easysync2.js
deleted file mode 100644
index cef868a1d..000000000
--- a/static/js/easysync2.js
+++ /dev/null
@@ -1,2513 +0,0 @@
-/**
- * This code is mostly from the old Etherpad. Please help us to comment this code. 
- * This helps other people to understand this code better and helps them to improve it.
- * TL;DR COMMENTS ON THIS FILE ARE HIGHLY APPRECIATED
- */
-
-// THIS FILE IS ALSO AN APPJET MODULE: etherpad.collab.ace.easysync2
-// %APPJET%: jimport("com.etherpad.Easysync2Support");
-/**
- * Copyright 2009 Google Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS-IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-//var _opt = (this.Easysync2Support || null);
-var _opt = null; // disable optimization for now
-
-function AttribPool()
-{
-  var p = {};
-  p.numToAttrib = {}; // e.g. {0: ['foo','bar']}
-  p.attribToNum = {}; // e.g. {'foo,bar': 0}
-  p.nextNum = 0;
-
-  p.putAttrib = function(attrib, dontAddIfAbsent)
-  {
-    var str = String(attrib);
-    if (str in p.attribToNum)
-    {
-      return p.attribToNum[str];
-    }
-    if (dontAddIfAbsent)
-    {
-      return -1;
-    }
-    var num = p.nextNum++;
-    p.attribToNum[str] = num;
-    p.numToAttrib[num] = [String(attrib[0] || ''), String(attrib[1] || '')];
-    return num;
-  };
-
-  p.getAttrib = function(num)
-  {
-    var pair = p.numToAttrib[num];
-    if (!pair) return pair;
-    return [pair[0], pair[1]]; // return a mutable copy
-  };
-
-  p.getAttribKey = function(num)
-  {
-    var pair = p.numToAttrib[num];
-    if (!pair) return '';
-    return pair[0];
-  };
-
-  p.getAttribValue = function(num)
-  {
-    var pair = p.numToAttrib[num];
-    if (!pair) return '';
-    return pair[1];
-  };
-
-  p.eachAttrib = function(func)
-  {
-    for (var n in p.numToAttrib)
-    {
-      var pair = p.numToAttrib[n];
-      func(pair[0], pair[1]);
-    }
-  };
-
-  p.toJsonable = function()
-  {
-    return {
-      numToAttrib: p.numToAttrib,
-      nextNum: p.nextNum
-    };
-  };
-
-  p.fromJsonable = function(obj)
-  {
-    p.numToAttrib = obj.numToAttrib;
-    p.nextNum = obj.nextNum;
-    p.attribToNum = {};
-    for (var n in p.numToAttrib)
-    {
-      p.attribToNum[String(p.numToAttrib[n])] = Number(n);
-    }
-    return p;
-  };
-
-  return p;
-}
-
-var Changeset = {};
-
-Changeset.error = function error(msg)
-{
-  var e = new Error(msg);
-  e.easysync = true;
-  throw e;
-};
-Changeset.assert = function assert(b, msgParts)
-{
-  if (!b)
-  {
-    var msg = Array.prototype.slice.call(arguments, 1).join('');
-    Changeset.error("Changeset: " + msg);
-  }
-};
-
-Changeset.parseNum = function(str)
-{
-  return parseInt(str, 36);
-};
-Changeset.numToString = function(num)
-{
-  return num.toString(36).toLowerCase();
-};
-Changeset.toBaseTen = function(cs)
-{
-  var dollarIndex = cs.indexOf('$');
-  var beforeDollar = cs.substring(0, dollarIndex);
-  var fromDollar = cs.substring(dollarIndex);
-  return beforeDollar.replace(/[0-9a-z]+/g, function(s)
-  {
-    return String(Changeset.parseNum(s));
-  }) + fromDollar;
-};
-
-Changeset.oldLen = function(cs)
-{
-  return Changeset.unpack(cs).oldLen;
-};
-Changeset.newLen = function(cs)
-{
-  return Changeset.unpack(cs).newLen;
-};
-
-Changeset.opIterator = function(opsStr, optStartIndex)
-{
-  //print(opsStr);
-  var regex = /((?:\*[0-9a-z]+)*)(?:\|([0-9a-z]+))?([-+=])([0-9a-z]+)|\?|/g;
-  var startIndex = (optStartIndex || 0);
-  var curIndex = startIndex;
-  var prevIndex = curIndex;
-
-  function nextRegexMatch()
-  {
-    prevIndex = curIndex;
-    var result;
-    if (_opt)
-    {
-      result = _opt.nextOpInString(opsStr, curIndex);
-      if (result)
-      {
-        if (result.opcode() == '?')
-        {
-          Changeset.error("Hit error opcode in op stream");
-        }
-        curIndex = result.lastIndex();
-      }
-    }
-    else
-    {
-      regex.lastIndex = curIndex;
-      result = regex.exec(opsStr);
-      curIndex = regex.lastIndex;
-      if (result[0] == '?')
-      {
-        Changeset.error("Hit error opcode in op stream");
-      }
-    }
-    return result;
-  }
-  var regexResult = nextRegexMatch();
-  var obj = Changeset.newOp();
-
-  function next(optObj)
-  {
-    var op = (optObj || obj);
-    if (_opt && regexResult)
-    {
-      op.attribs = regexResult.attribs();
-      op.lines = regexResult.lines();
-      op.chars = regexResult.chars();
-      op.opcode = regexResult.opcode();
-      regexResult = nextRegexMatch();
-    }
-    else if ((!_opt) && regexResult[0])
-    {
-      op.attribs = regexResult[1];
-      op.lines = Changeset.parseNum(regexResult[2] || 0);
-      op.opcode = regexResult[3];
-      op.chars = Changeset.parseNum(regexResult[4]);
-      regexResult = nextRegexMatch();
-    }
-    else
-    {
-      Changeset.clearOp(op);
-    }
-    return op;
-  }
-
-  function hasNext()
-  {
-    return !!(_opt ? regexResult : regexResult[0]);
-  }
-
-  function lastIndex()
-  {
-    return prevIndex;
-  }
-  return {
-    next: next,
-    hasNext: hasNext,
-    lastIndex: lastIndex
-  };
-};
-
-Changeset.clearOp = function(op)
-{
-  op.opcode = '';
-  op.chars = 0;
-  op.lines = 0;
-  op.attribs = '';
-};
-Changeset.newOp = function(optOpcode)
-{
-  return {
-    opcode: (optOpcode || ''),
-    chars: 0,
-    lines: 0,
-    attribs: ''
-  };
-};
-Changeset.cloneOp = function(op)
-{
-  return {
-    opcode: op.opcode,
-    chars: op.chars,
-    lines: op.lines,
-    attribs: op.attribs
-  };
-};
-Changeset.copyOp = function(op1, op2)
-{
-  op2.opcode = op1.opcode;
-  op2.chars = op1.chars;
-  op2.lines = op1.lines;
-  op2.attribs = op1.attribs;
-};
-Changeset.opString = function(op)
-{
-  // just for debugging
-  if (!op.opcode) return 'null';
-  var assem = Changeset.opAssembler();
-  assem.append(op);
-  return assem.toString();
-};
-Changeset.stringOp = function(str)
-{
-  // just for debugging
-  return Changeset.opIterator(str).next();
-};
-
-Changeset.checkRep = function(cs)
-{
-  // doesn't check things that require access to attrib pool (e.g. attribute order)
-  // or original string (e.g. newline positions)
-  var unpacked = Changeset.unpack(cs);
-  var oldLen = unpacked.oldLen;
-  var newLen = unpacked.newLen;
-  var ops = unpacked.ops;
-  var charBank = unpacked.charBank;
-
-  var assem = Changeset.smartOpAssembler();
-  var oldPos = 0;
-  var calcNewLen = 0;
-  var numInserted = 0;
-  var iter = Changeset.opIterator(ops);
-  while (iter.hasNext())
-  {
-    var o = iter.next();
-    switch (o.opcode)
-    {
-    case '=':
-      oldPos += o.chars;
-      calcNewLen += o.chars;
-      break;
-    case '-':
-      oldPos += o.chars;
-      Changeset.assert(oldPos < oldLen, oldPos, " >= ", oldLen, " in ", cs);
-      break;
-    case '+':
-      {
-        calcNewLen += o.chars;
-        numInserted += o.chars;
-        Changeset.assert(calcNewLen < newLen, calcNewLen, " >= ", newLen, " in ", cs);
-        break;
-      }
-    }
-    assem.append(o);
-  }
-
-  calcNewLen += oldLen - oldPos;
-  charBank = charBank.substring(0, numInserted);
-  while (charBank.length < numInserted)
-  {
-    charBank += "?";
-  }
-
-  assem.endDocument();
-  var normalized = Changeset.pack(oldLen, calcNewLen, assem.toString(), charBank);
-  Changeset.assert(normalized == cs, normalized, ' != ', cs);
-
-  return cs;
-}
-
-Changeset.smartOpAssembler = function()
-{
-  // Like opAssembler but able to produce conforming changesets
-  // from slightly looser input, at the cost of speed.
-  // Specifically:
-  // - merges consecutive operations that can be merged
-  // - strips final "="
-  // - ignores 0-length changes
-  // - reorders consecutive + and - (which margingOpAssembler doesn't do)
-  var minusAssem = Changeset.mergingOpAssembler();
-  var plusAssem = Changeset.mergingOpAssembler();
-  var keepAssem = Changeset.mergingOpAssembler();
-  var assem = Changeset.stringAssembler();
-  var lastOpcode = '';
-  var lengthChange = 0;
-
-  function flushKeeps()
-  {
-    assem.append(keepAssem.toString());
-    keepAssem.clear();
-  }
-
-  function flushPlusMinus()
-  {
-    assem.append(minusAssem.toString());
-    minusAssem.clear();
-    assem.append(plusAssem.toString());
-    plusAssem.clear();
-  }
-
-  function append(op)
-  {
-    if (!op.opcode) return;
-    if (!op.chars) return;
-
-    if (op.opcode == '-')
-    {
-      if (lastOpcode == '=')
-      {
-        flushKeeps();
-      }
-      minusAssem.append(op);
-      lengthChange -= op.chars;
-    }
-    else if (op.opcode == '+')
-    {
-      if (lastOpcode == '=')
-      {
-        flushKeeps();
-      }
-      plusAssem.append(op);
-      lengthChange += op.chars;
-    }
-    else if (op.opcode == '=')
-    {
-      if (lastOpcode != '=')
-      {
-        flushPlusMinus();
-      }
-      keepAssem.append(op);
-    }
-    lastOpcode = op.opcode;
-  }
-
-  function appendOpWithText(opcode, text, attribs, pool)
-  {
-    var op = Changeset.newOp(opcode);
-    op.attribs = Changeset.makeAttribsString(opcode, attribs, pool);
-    var lastNewlinePos = text.lastIndexOf('\n');
-    if (lastNewlinePos < 0)
-    {
-      op.chars = text.length;
-      op.lines = 0;
-      append(op);
-    }
-    else
-    {
-      op.chars = lastNewlinePos + 1;
-      op.lines = text.match(/\n/g).length;
-      append(op);
-      op.chars = text.length - (lastNewlinePos + 1);
-      op.lines = 0;
-      append(op);
-    }
-  }
-
-  function toString()
-  {
-    flushPlusMinus();
-    flushKeeps();
-    return assem.toString();
-  }
-
-  function clear()
-  {
-    minusAssem.clear();
-    plusAssem.clear();
-    keepAssem.clear();
-    assem.clear();
-    lengthChange = 0;
-  }
-
-  function endDocument()
-  {
-    keepAssem.endDocument();
-  }
-
-  function getLengthChange()
-  {
-    return lengthChange;
-  }
-
-  return {
-    append: append,
-    toString: toString,
-    clear: clear,
-    endDocument: endDocument,
-    appendOpWithText: appendOpWithText,
-    getLengthChange: getLengthChange
-  };
-};
-
-if (_opt)
-{
-  Changeset.mergingOpAssembler = function()
-  {
-    var assem = _opt.mergingOpAssembler();
-
-    function append(op)
-    {
-      assem.append(op.opcode, op.chars, op.lines, op.attribs);
-    }
-
-    function toString()
-    {
-      return assem.toString();
-    }
-
-    function clear()
-    {
-      assem.clear();
-    }
-
-    function endDocument()
-    {
-      assem.endDocument();
-    }
-
-    return {
-      append: append,
-      toString: toString,
-      clear: clear,
-      endDocument: endDocument
-    };
-  };
-}
-else
-{
-  Changeset.mergingOpAssembler = function()
-  {
-    // This assembler can be used in production; it efficiently
-    // merges consecutive operations that are mergeable, ignores
-    // no-ops, and drops final pure "keeps".  It does not re-order
-    // operations.
-    var assem = Changeset.opAssembler();
-    var bufOp = Changeset.newOp();
-
-    // If we get, for example, insertions [xxx\n,yyy], those don't merge,
-    // but if we get [xxx\n,yyy,zzz\n], that merges to [xxx\nyyyzzz\n].
-    // This variable stores the length of yyy and any other newline-less
-    // ops immediately after it.
-    var bufOpAdditionalCharsAfterNewline = 0;
-
-    function flush(isEndDocument)
-    {
-      if (bufOp.opcode)
-      {
-        if (isEndDocument && bufOp.opcode == '=' && !bufOp.attribs)
-        {
-          // final merged keep, leave it implicit
-        }
-        else
-        {
-          assem.append(bufOp);
-          if (bufOpAdditionalCharsAfterNewline)
-          {
-            bufOp.chars = bufOpAdditionalCharsAfterNewline;
-            bufOp.lines = 0;
-            assem.append(bufOp);
-            bufOpAdditionalCharsAfterNewline = 0;
-          }
-        }
-        bufOp.opcode = '';
-      }
-    }
-
-    function append(op)
-    {
-      if (op.chars > 0)
-      {
-        if (bufOp.opcode == op.opcode && bufOp.attribs == op.attribs)
-        {
-          if (op.lines > 0)
-          {
-            // bufOp and additional chars are all mergeable into a multi-line op
-            bufOp.chars += bufOpAdditionalCharsAfterNewline + op.chars;
-            bufOp.lines += op.lines;
-            bufOpAdditionalCharsAfterNewline = 0;
-          }
-          else if (bufOp.lines == 0)
-          {
-            // both bufOp and op are in-line
-            bufOp.chars += op.chars;
-          }
-          else
-          {
-            // append in-line text to multi-line bufOp
-            bufOpAdditionalCharsAfterNewline += op.chars;
-          }
-        }
-        else
-        {
-          flush();
-          Changeset.copyOp(op, bufOp);
-        }
-      }
-    }
-
-    function endDocument()
-    {
-      flush(true);
-    }
-
-    function toString()
-    {
-      flush();
-      return assem.toString();
-    }
-
-    function clear()
-    {
-      assem.clear();
-      Changeset.clearOp(bufOp);
-    }
-    return {
-      append: append,
-      toString: toString,
-      clear: clear,
-      endDocument: endDocument
-    };
-  };
-}
-
-if (_opt)
-{
-  Changeset.opAssembler = function()
-  {
-    var assem = _opt.opAssembler();
-    // this function allows op to be mutated later (doesn't keep a ref)
-
-
-    function append(op)
-    {
-      assem.append(op.opcode, op.chars, op.lines, op.attribs);
-    }
-
-    function toString()
-    {
-      return assem.toString();
-    }
-
-    function clear()
-    {
-      assem.clear();
-    }
-    return {
-      append: append,
-      toString: toString,
-      clear: clear
-    };
-  };
-}
-else
-{
-  Changeset.opAssembler = function()
-  {
-    var pieces = [];
-    // this function allows op to be mutated later (doesn't keep a ref)
-
-
-    function append(op)
-    {
-      pieces.push(op.attribs);
-      if (op.lines)
-      {
-        pieces.push('|', Changeset.numToString(op.lines));
-      }
-      pieces.push(op.opcode);
-      pieces.push(Changeset.numToString(op.chars));
-    }
-
-    function toString()
-    {
-      return pieces.join('');
-    }
-
-    function clear()
-    {
-      pieces.length = 0;
-    }
-    return {
-      append: append,
-      toString: toString,
-      clear: clear
-    };
-  };
-}
-
-Changeset.stringIterator = function(str)
-{
-  var curIndex = 0;
-
-  function assertRemaining(n)
-  {
-    Changeset.assert(n <= remaining(), "!(", n, " <= ", remaining(), ")");
-  }
-
-  function take(n)
-  {
-    assertRemaining(n);
-    var s = str.substr(curIndex, n);
-    curIndex += n;
-    return s;
-  }
-
-  function peek(n)
-  {
-    assertRemaining(n);
-    var s = str.substr(curIndex, n);
-    return s;
-  }
-
-  function skip(n)
-  {
-    assertRemaining(n);
-    curIndex += n;
-  }
-
-  function remaining()
-  {
-    return str.length - curIndex;
-  }
-  return {
-    take: take,
-    skip: skip,
-    remaining: remaining,
-    peek: peek
-  };
-};
-
-Changeset.stringAssembler = function()
-{
-  var pieces = [];
-
-  function append(x)
-  {
-    pieces.push(String(x));
-  }
-
-  function toString()
-  {
-    return pieces.join('');
-  }
-  return {
-    append: append,
-    toString: toString
-  };
-};
-
-// "lines" need not be an array as long as it supports certain calls (lines_foo inside).
-Changeset.textLinesMutator = function(lines)
-{
-  // Mutates lines, an array of strings, in place.
-  // Mutation operations have the same constraints as changeset operations
-  // with respect to newlines, but not the other additional constraints
-  // (i.e. ins/del ordering, forbidden no-ops, non-mergeability, final newline).
-  // Can be used to mutate lists of strings where the last char of each string
-  // is not actually a newline, but for the purposes of N and L values,
-  // the caller should pretend it is, and for things to work right in that case, the input
-  // to insert() should be a single line with no newlines.
-  var curSplice = [0, 0];
-  var inSplice = false;
-  // position in document after curSplice is applied:
-  var curLine = 0,
-      curCol = 0;
-  // invariant: if (inSplice) then (curLine is in curSplice[0] + curSplice.length - {2,3}) &&
-  //            curLine >= curSplice[0]
-  // invariant: if (inSplice && (curLine >= curSplice[0] + curSplice.length - 2)) then
-  //            curCol == 0
-
-  function lines_applySplice(s)
-  {
-    lines.splice.apply(lines, s);
-  }
-
-  function lines_toSource()
-  {
-    return lines.toSource();
-  }
-
-  function lines_get(idx)
-  {
-    if (lines.get)
-    {
-      return lines.get(idx);
-    }
-    else
-    {
-      return lines[idx];
-    }
-  }
-  // can be unimplemented if removeLines's return value not needed
-
-
-  function lines_slice(start, end)
-  {
-    if (lines.slice)
-    {
-      return lines.slice(start, end);
-    }
-    else
-    {
-      return [];
-    }
-  }
-
-  function lines_length()
-  {
-    if ((typeof lines.length) == "number")
-    {
-      return lines.length;
-    }
-    else
-    {
-      return lines.length();
-    }
-  }
-
-  function enterSplice()
-  {
-    curSplice[0] = curLine;
-    curSplice[1] = 0;
-    if (curCol > 0)
-    {
-      putCurLineInSplice();
-    }
-    inSplice = true;
-  }
-
-  function leaveSplice()
-  {
-    lines_applySplice(curSplice);
-    curSplice.length = 2;
-    curSplice[0] = curSplice[1] = 0;
-    inSplice = false;
-  }
-
-  function isCurLineInSplice()
-  {
-    return (curLine - curSplice[0] < (curSplice.length - 2));
-  }
-
-  function debugPrint(typ)
-  {
-    print(typ + ": " + curSplice.toSource() + " / " + curLine + "," + curCol + " / " + lines_toSource());
-  }
-
-  function putCurLineInSplice()
-  {
-    if (!isCurLineInSplice())
-    {
-      curSplice.push(lines_get(curSplice[0] + curSplice[1]));
-      curSplice[1]++;
-    }
-    return 2 + curLine - curSplice[0];
-  }
-
-  function skipLines(L, includeInSplice)
-  {
-    if (L)
-    {
-      if (includeInSplice)
-      {
-        if (!inSplice)
-        {
-          enterSplice();
-        }
-        for (var i = 0; i < L; i++)
-        {
-          curCol = 0;
-          putCurLineInSplice();
-          curLine++;
-        }
-      }
-      else
-      {
-        if (inSplice)
-        {
-          if (L > 1)
-          {
-            leaveSplice();
-          }
-          else
-          {
-            putCurLineInSplice();
-          }
-        }
-        curLine += L;
-        curCol = 0;
-      }
-      //print(inSplice+" / "+isCurLineInSplice()+" / "+curSplice[0]+" / "+curSplice[1]+" / "+lines.length);
-/*if (inSplice && (! isCurLineInSplice()) && (curSplice[0] + curSplice[1] < lines.length)) {
-	  print("BLAH");
-	  putCurLineInSplice();
-	}*/
-      // tests case foo in remove(), which isn't otherwise covered in current impl
-    }
-    //debugPrint("skip");
-  }
-
-  function skip(N, L, includeInSplice)
-  {
-    if (N)
-    {
-      if (L)
-      {
-        skipLines(L, includeInSplice);
-      }
-      else
-      {
-        if (includeInSplice && !inSplice)
-        {
-          enterSplice();
-        }
-        if (inSplice)
-        {
-          putCurLineInSplice();
-        }
-        curCol += N;
-        //debugPrint("skip");
-      }
-    }
-  }
-
-  function removeLines(L)
-  {
-    var removed = '';
-    if (L)
-    {
-      if (!inSplice)
-      {
-        enterSplice();
-      }
-
-      function nextKLinesText(k)
-      {
-        var m = curSplice[0] + curSplice[1];
-        return lines_slice(m, m + k).join('');
-      }
-      if (isCurLineInSplice())
-      {
-        //print(curCol);
-        if (curCol == 0)
-        {
-          removed = curSplice[curSplice.length - 1];
-          // print("FOO"); // case foo
-          curSplice.length--;
-          removed += nextKLinesText(L - 1);
-          curSplice[1] += L - 1;
-        }
-        else
-        {
-          removed = nextKLinesText(L - 1);
-          curSplice[1] += L - 1;
-          var sline = curSplice.length - 1;
-          removed = curSplice[sline].substring(curCol) + removed;
-          curSplice[sline] = curSplice[sline].substring(0, curCol) + lines_get(curSplice[0] + curSplice[1]);
-          curSplice[1] += 1;
-        }
-      }
-      else
-      {
-        removed = nextKLinesText(L);
-        curSplice[1] += L;
-      }
-      //debugPrint("remove");
-    }
-    return removed;
-  }
-
-  function remove(N, L)
-  {
-    var removed = '';
-    if (N)
-    {
-      if (L)
-      {
-        return removeLines(L);
-      }
-      else
-      {
-        if (!inSplice)
-        {
-          enterSplice();
-        }
-        var sline = putCurLineInSplice();
-        removed = curSplice[sline].substring(curCol, curCol + N);
-        curSplice[sline] = curSplice[sline].substring(0, curCol) + curSplice[sline].substring(curCol + N);
-        //debugPrint("remove");
-      }
-    }
-    return removed;
-  }
-
-  function insert(text, L)
-  {
-    if (text)
-    {
-      if (!inSplice)
-      {
-        enterSplice();
-      }
-      if (L)
-      {
-        var newLines = Changeset.splitTextLines(text);
-        if (isCurLineInSplice())
-        {
-          //if (curCol == 0) {
-          //curSplice.length--;
-          //curSplice[1]--;
-          //Array.prototype.push.apply(curSplice, newLines);
-          //curLine += newLines.length;
-          //}
-          //else {
-          var sline = curSplice.length - 1;
-          var theLine = curSplice[sline];
-          var lineCol = curCol;
-          curSplice[sline] = theLine.substring(0, lineCol) + newLines[0];
-          curLine++;
-          newLines.splice(0, 1);
-          Array.prototype.push.apply(curSplice, newLines);
-          curLine += newLines.length;
-          curSplice.push(theLine.substring(lineCol));
-          curCol = 0;
-          //}
-        }
-        else
-        {
-          Array.prototype.push.apply(curSplice, newLines);
-          curLine += newLines.length;
-        }
-      }
-      else
-      {
-        var sline = putCurLineInSplice();
-        curSplice[sline] = curSplice[sline].substring(0, curCol) + text + curSplice[sline].substring(curCol);
-        curCol += text.length;
-      }
-      //debugPrint("insert");
-    }
-  }
-
-  function hasMore()
-  {
-    //print(lines.length+" / "+inSplice+" / "+(curSplice.length - 2)+" / "+curSplice[1]);
-    var docLines = lines_length();
-    if (inSplice)
-    {
-      docLines += curSplice.length - 2 - curSplice[1];
-    }
-    return curLine < docLines;
-  }
-
-  function close()
-  {
-    if (inSplice)
-    {
-      leaveSplice();
-    }
-    //debugPrint("close");
-  }
-
-  var self = {
-    skip: skip,
-    remove: remove,
-    insert: insert,
-    close: close,
-    hasMore: hasMore,
-    removeLines: removeLines,
-    skipLines: skipLines
-  };
-  return self;
-};
-
-Changeset.applyZip = function(in1, idx1, in2, idx2, func)
-{
-  var iter1 = Changeset.opIterator(in1, idx1);
-  var iter2 = Changeset.opIterator(in2, idx2);
-  var assem = Changeset.smartOpAssembler();
-  var op1 = Changeset.newOp();
-  var op2 = Changeset.newOp();
-  var opOut = Changeset.newOp();
-  while (op1.opcode || iter1.hasNext() || op2.opcode || iter2.hasNext())
-  {
-    if ((!op1.opcode) && iter1.hasNext()) iter1.next(op1);
-    if ((!op2.opcode) && iter2.hasNext()) iter2.next(op2);
-    func(op1, op2, opOut);
-    if (opOut.opcode)
-    {
-      //print(opOut.toSource());
-      assem.append(opOut);
-      opOut.opcode = '';
-    }
-  }
-  assem.endDocument();
-  return assem.toString();
-};
-
-Changeset.unpack = function(cs)
-{
-  var headerRegex = /Z:([0-9a-z]+)([><])([0-9a-z]+)|/;
-  var headerMatch = headerRegex.exec(cs);
-  if ((!headerMatch) || (!headerMatch[0]))
-  {
-    Changeset.error("Not a changeset: " + cs);
-  }
-  var oldLen = Changeset.parseNum(headerMatch[1]);
-  var changeSign = (headerMatch[2] == '>') ? 1 : -1;
-  var changeMag = Changeset.parseNum(headerMatch[3]);
-  var newLen = oldLen + changeSign * changeMag;
-  var opsStart = headerMatch[0].length;
-  var opsEnd = cs.indexOf("$");
-  if (opsEnd < 0) opsEnd = cs.length;
-  return {
-    oldLen: oldLen,
-    newLen: newLen,
-    ops: cs.substring(opsStart, opsEnd),
-    charBank: cs.substring(opsEnd + 1)
-  };
-};
-
-Changeset.pack = function(oldLen, newLen, opsStr, bank)
-{
-  var lenDiff = newLen - oldLen;
-  var lenDiffStr = (lenDiff >= 0 ? '>' + Changeset.numToString(lenDiff) : '<' + Changeset.numToString(-lenDiff));
-  var a = [];
-  a.push('Z:', Changeset.numToString(oldLen), lenDiffStr, opsStr, '$', bank);
-  return a.join('');
-};
-
-Changeset.applyToText = function(cs, str)
-{
-  var unpacked = Changeset.unpack(cs);
-  Changeset.assert(str.length == unpacked.oldLen, "mismatched apply: ", str.length, " / ", unpacked.oldLen);
-  var csIter = Changeset.opIterator(unpacked.ops);
-  var bankIter = Changeset.stringIterator(unpacked.charBank);
-  var strIter = Changeset.stringIterator(str);
-  var assem = Changeset.stringAssembler();
-  while (csIter.hasNext())
-  {
-    var op = csIter.next();
-    switch (op.opcode)
-    {
-    case '+':
-      assem.append(bankIter.take(op.chars));
-      break;
-    case '-':
-      strIter.skip(op.chars);
-      break;
-    case '=':
-      assem.append(strIter.take(op.chars));
-      break;
-    }
-  }
-  assem.append(strIter.take(strIter.remaining()));
-  return assem.toString();
-};
-
-Changeset.mutateTextLines = function(cs, lines)
-{
-  var unpacked = Changeset.unpack(cs);
-  var csIter = Changeset.opIterator(unpacked.ops);
-  var bankIter = Changeset.stringIterator(unpacked.charBank);
-  var mut = Changeset.textLinesMutator(lines);
-  while (csIter.hasNext())
-  {
-    var op = csIter.next();
-    switch (op.opcode)
-    {
-    case '+':
-      mut.insert(bankIter.take(op.chars), op.lines);
-      break;
-    case '-':
-      mut.remove(op.chars, op.lines);
-      break;
-    case '=':
-      mut.skip(op.chars, op.lines, ( !! op.attribs));
-      break;
-    }
-  }
-  mut.close();
-};
-
-Changeset.composeAttributes = function(att1, att2, resultIsMutation, pool)
-{
-  // att1 and att2 are strings like "*3*f*1c", asMutation is a boolean.
-  // Sometimes attribute (key,value) pairs are treated as attribute presence
-  // information, while other times they are treated as operations that
-  // mutate a set of attributes, and this affects whether an empty value
-  // is a deletion or a change.
-  // Examples, of the form (att1Items, att2Items, resultIsMutation) -> result
-  // ([], [(bold, )], true) -> [(bold, )]
-  // ([], [(bold, )], false) -> []
-  // ([], [(bold, true)], true) -> [(bold, true)]
-  // ([], [(bold, true)], false) -> [(bold, true)]
-  // ([(bold, true)], [(bold, )], true) -> [(bold, )]
-  // ([(bold, true)], [(bold, )], false) -> []
-  // pool can be null if att2 has no attributes.
-  if ((!att1) && resultIsMutation)
-  {
-    // In the case of a mutation (i.e. composing two changesets),
-    // an att2 composed with an empy att1 is just att2.  If att1
-    // is part of an attribution string, then att2 may remove
-    // attributes that are already gone, so don't do this optimization.
-    return att2;
-  }
-  if (!att2) return att1;
-  var atts = [];
-  att1.replace(/\*([0-9a-z]+)/g, function(_, a)
-  {
-    atts.push(pool.getAttrib(Changeset.parseNum(a)));
-    return '';
-  });
-  att2.replace(/\*([0-9a-z]+)/g, function(_, a)
-  {
-    var pair = pool.getAttrib(Changeset.parseNum(a));
-    var found = false;
-    for (var i = 0; i < atts.length; i++)
-    {
-      var oldPair = atts[i];
-      if (oldPair[0] == pair[0])
-      {
-        if (pair[1] || resultIsMutation)
-        {
-          oldPair[1] = pair[1];
-        }
-        else
-        {
-          atts.splice(i, 1);
-        }
-        found = true;
-        break;
-      }
-    }
-    if ((!found) && (pair[1] || resultIsMutation))
-    {
-      atts.push(pair);
-    }
-    return '';
-  });
-  atts.sort();
-  var buf = Changeset.stringAssembler();
-  for (var i = 0; i < atts.length; i++)
-  {
-    buf.append('*');
-    buf.append(Changeset.numToString(pool.putAttrib(atts[i])));
-  }
-  //print(att1+" / "+att2+" / "+buf.toString());
-  return buf.toString();
-};
-
-Changeset._slicerZipperFunc = function(attOp, csOp, opOut, pool)
-{
-  // attOp is the op from the sequence that is being operated on, either an
-  // attribution string or the earlier of two changesets being composed.
-  // pool can be null if definitely not needed.
-  //print(csOp.toSource()+" "+attOp.toSource()+" "+opOut.toSource());
-  if (attOp.opcode == '-')
-  {
-    Changeset.copyOp(attOp, opOut);
-    attOp.opcode = '';
-  }
-  else if (!attOp.opcode)
-  {
-    Changeset.copyOp(csOp, opOut);
-    csOp.opcode = '';
-  }
-  else
-  {
-    switch (csOp.opcode)
-    {
-    case '-':
-      {
-        if (csOp.chars <= attOp.chars)
-        {
-          // delete or delete part
-          if (attOp.opcode == '=')
-          {
-            opOut.opcode = '-';
-            opOut.chars = csOp.chars;
-            opOut.lines = csOp.lines;
-            opOut.attribs = '';
-          }
-          attOp.chars -= csOp.chars;
-          attOp.lines -= csOp.lines;
-          csOp.opcode = '';
-          if (!attOp.chars)
-          {
-            attOp.opcode = '';
-          }
-        }
-        else
-        {
-          // delete and keep going
-          if (attOp.opcode == '=')
-          {
-            opOut.opcode = '-';
-            opOut.chars = attOp.chars;
-            opOut.lines = attOp.lines;
-            opOut.attribs = '';
-          }
-          csOp.chars -= attOp.chars;
-          csOp.lines -= attOp.lines;
-          attOp.opcode = '';
-        }
-        break;
-      }
-    case '+':
-      {
-        // insert
-        Changeset.copyOp(csOp, opOut);
-        csOp.opcode = '';
-        break;
-      }
-    case '=':
-      {
-        if (csOp.chars <= attOp.chars)
-        {
-          // keep or keep part
-          opOut.opcode = attOp.opcode;
-          opOut.chars = csOp.chars;
-          opOut.lines = csOp.lines;
-          opOut.attribs = Changeset.composeAttributes(attOp.attribs, csOp.attribs, attOp.opcode == '=', pool);
-          csOp.opcode = '';
-          attOp.chars -= csOp.chars;
-          attOp.lines -= csOp.lines;
-          if (!attOp.chars)
-          {
-            attOp.opcode = '';
-          }
-        }
-        else
-        {
-          // keep and keep going
-          opOut.opcode = attOp.opcode;
-          opOut.chars = attOp.chars;
-          opOut.lines = attOp.lines;
-          opOut.attribs = Changeset.composeAttributes(attOp.attribs, csOp.attribs, attOp.opcode == '=', pool);
-          attOp.opcode = '';
-          csOp.chars -= attOp.chars;
-          csOp.lines -= attOp.lines;
-        }
-        break;
-      }
-    case '':
-      {
-        Changeset.copyOp(attOp, opOut);
-        attOp.opcode = '';
-        break;
-      }
-    }
-  }
-};
-
-Changeset.applyToAttribution = function(cs, astr, pool)
-{
-  var unpacked = Changeset.unpack(cs);
-
-  return Changeset.applyZip(astr, 0, unpacked.ops, 0, function(op1, op2, opOut)
-  {
-    return Changeset._slicerZipperFunc(op1, op2, opOut, pool);
-  });
-};
-
-/*Changeset.oneInsertedLineAtATimeOpIterator = function(opsStr, optStartIndex, charBank) {
-  var iter = Changeset.opIterator(opsStr, optStartIndex);
-  var bankIndex = 0;
-
-};*/
-
-Changeset.mutateAttributionLines = function(cs, lines, pool)
-{
-  //dmesg(cs);
-  //dmesg(lines.toSource()+" ->");
-  var unpacked = Changeset.unpack(cs);
-  var csIter = Changeset.opIterator(unpacked.ops);
-  var csBank = unpacked.charBank;
-  var csBankIndex = 0;
-  // treat the attribution lines as text lines, mutating a line at a time
-  var mut = Changeset.textLinesMutator(lines);
-
-  var lineIter = null;
-
-  function isNextMutOp()
-  {
-    return (lineIter && lineIter.hasNext()) || mut.hasMore();
-  }
-
-  function nextMutOp(destOp)
-  {
-    if ((!(lineIter && lineIter.hasNext())) && mut.hasMore())
-    {
-      var line = mut.removeLines(1);
-      lineIter = Changeset.opIterator(line);
-    }
-    if (lineIter && lineIter.hasNext())
-    {
-      lineIter.next(destOp);
-    }
-    else
-    {
-      destOp.opcode = '';
-    }
-  }
-  var lineAssem = null;
-
-  function outputMutOp(op)
-  {
-    //print("outputMutOp: "+op.toSource());
-    if (!lineAssem)
-    {
-      lineAssem = Changeset.mergingOpAssembler();
-    }
-    lineAssem.append(op);
-    if (op.lines > 0)
-    {
-      Changeset.assert(op.lines == 1, "Can't have op.lines of ", op.lines, " in attribution lines");
-      // ship it to the mut
-      mut.insert(lineAssem.toString(), 1);
-      lineAssem = null;
-    }
-  }
-
-  var csOp = Changeset.newOp();
-  var attOp = Changeset.newOp();
-  var opOut = Changeset.newOp();
-  while (csOp.opcode || csIter.hasNext() || attOp.opcode || isNextMutOp())
-  {
-    if ((!csOp.opcode) && csIter.hasNext())
-    {
-      csIter.next(csOp);
-    }
-    //print(csOp.toSource()+" "+attOp.toSource()+" "+opOut.toSource());
-    //print(csOp.opcode+"/"+csOp.lines+"/"+csOp.attribs+"/"+lineAssem+"/"+lineIter+"/"+(lineIter?lineIter.hasNext():null));
-    //print("csOp: "+csOp.toSource());
-    if ((!csOp.opcode) && (!attOp.opcode) && (!lineAssem) && (!(lineIter && lineIter.hasNext())))
-    {
-      break; // done
-    }
-    else if (csOp.opcode == '=' && csOp.lines > 0 && (!csOp.attribs) && (!attOp.opcode) && (!lineAssem) && (!(lineIter && lineIter.hasNext())))
-    {
-      // skip multiple lines; this is what makes small changes not order of the document size
-      mut.skipLines(csOp.lines);
-      //print("skipped: "+csOp.lines);
-      csOp.opcode = '';
-    }
-    else if (csOp.opcode == '+')
-    {
-      if (csOp.lines > 1)
-      {
-        var firstLineLen = csBank.indexOf('\n', csBankIndex) + 1 - csBankIndex;
-        Changeset.copyOp(csOp, opOut);
-        csOp.chars -= firstLineLen;
-        csOp.lines--;
-        opOut.lines = 1;
-        opOut.chars = firstLineLen;
-      }
-      else
-      {
-        Changeset.copyOp(csOp, opOut);
-        csOp.opcode = '';
-      }
-      outputMutOp(opOut);
-      csBankIndex += opOut.chars;
-      opOut.opcode = '';
-    }
-    else
-    {
-      if ((!attOp.opcode) && isNextMutOp())
-      {
-        nextMutOp(attOp);
-      }
-      //print("attOp: "+attOp.toSource());
-      Changeset._slicerZipperFunc(attOp, csOp, opOut, pool);
-      if (opOut.opcode)
-      {
-        outputMutOp(opOut);
-        opOut.opcode = '';
-      }
-    }
-  }
-
-  Changeset.assert(!lineAssem, "line assembler not finished");
-  mut.close();
-
-  //dmesg("-> "+lines.toSource());
-};
-
-Changeset.joinAttributionLines = function(theAlines)
-{
-  var assem = Changeset.mergingOpAssembler();
-  for (var i = 0; i < theAlines.length; i++)
-  {
-    var aline = theAlines[i];
-    var iter = Changeset.opIterator(aline);
-    while (iter.hasNext())
-    {
-      assem.append(iter.next());
-    }
-  }
-  return assem.toString();
-};
-
-Changeset.splitAttributionLines = function(attrOps, text)
-{
-  var iter = Changeset.opIterator(attrOps);
-  var assem = Changeset.mergingOpAssembler();
-  var lines = [];
-  var pos = 0;
-
-  function appendOp(op)
-  {
-    assem.append(op);
-    if (op.lines > 0)
-    {
-      lines.push(assem.toString());
-      assem.clear();
-    }
-    pos += op.chars;
-  }
-
-  while (iter.hasNext())
-  {
-    var op = iter.next();
-    var numChars = op.chars;
-    var numLines = op.lines;
-    while (numLines > 1)
-    {
-      var newlineEnd = text.indexOf('\n', pos) + 1;
-      Changeset.assert(newlineEnd > 0, "newlineEnd <= 0 in splitAttributionLines");
-      op.chars = newlineEnd - pos;
-      op.lines = 1;
-      appendOp(op);
-      numChars -= op.chars;
-      numLines -= op.lines;
-    }
-    if (numLines == 1)
-    {
-      op.chars = numChars;
-      op.lines = 1;
-    }
-    appendOp(op);
-  }
-
-  return lines;
-};
-
-Changeset.splitTextLines = function(text)
-{
-  return text.match(/[^\n]*(?:\n|[^\n]$)/g);
-};
-
-Changeset.compose = function(cs1, cs2, pool)
-{
-  var unpacked1 = Changeset.unpack(cs1);
-  var unpacked2 = Changeset.unpack(cs2);
-  var len1 = unpacked1.oldLen;
-  var len2 = unpacked1.newLen;
-  Changeset.assert(len2 == unpacked2.oldLen, "mismatched composition");
-  var len3 = unpacked2.newLen;
-  var bankIter1 = Changeset.stringIterator(unpacked1.charBank);
-  var bankIter2 = Changeset.stringIterator(unpacked2.charBank);
-  var bankAssem = Changeset.stringAssembler();
-
-  var newOps = Changeset.applyZip(unpacked1.ops, 0, unpacked2.ops, 0, function(op1, op2, opOut)
-  {
-    //var debugBuilder = Changeset.stringAssembler();
-    //debugBuilder.append(Changeset.opString(op1));
-    //debugBuilder.append(',');
-    //debugBuilder.append(Changeset.opString(op2));
-    //debugBuilder.append(' / ');
-    var op1code = op1.opcode;
-    var op2code = op2.opcode;
-    if (op1code == '+' && op2code == '-')
-    {
-      bankIter1.skip(Math.min(op1.chars, op2.chars));
-    }
-    Changeset._slicerZipperFunc(op1, op2, opOut, pool);
-    if (opOut.opcode == '+')
-    {
-      if (op2code == '+')
-      {
-        bankAssem.append(bankIter2.take(opOut.chars));
-      }
-      else
-      {
-        bankAssem.append(bankIter1.take(opOut.chars));
-      }
-    }
-
-    //debugBuilder.append(Changeset.opString(op1));
-    //debugBuilder.append(',');
-    //debugBuilder.append(Changeset.opString(op2));
-    //debugBuilder.append(' -> ');
-    //debugBuilder.append(Changeset.opString(opOut));
-    //print(debugBuilder.toString());
-  });
-
-  return Changeset.pack(len1, len3, newOps, bankAssem.toString());
-};
-
-Changeset.attributeTester = function(attribPair, pool)
-{
-  // returns a function that tests if a string of attributes
-  // (e.g. *3*4) contains a given attribute key,value that
-  // is already present in the pool.
-  if (!pool)
-  {
-    return never;
-  }
-  var attribNum = pool.putAttrib(attribPair, true);
-  if (attribNum < 0)
-  {
-    return never;
-  }
-  else
-  {
-    var re = new RegExp('\\*' + Changeset.numToString(attribNum) + '(?!\\w)');
-    return function(attribs)
-    {
-      return re.test(attribs);
-    };
-  }
-
-  function never(attribs)
-  {
-    return false;
-  }
-};
-
-Changeset.identity = function(N)
-{
-  return Changeset.pack(N, N, "", "");
-};
-
-Changeset.makeSplice = function(oldFullText, spliceStart, numRemoved, newText, optNewTextAPairs, pool)
-{
-  var oldLen = oldFullText.length;
-
-  if (spliceStart >= oldLen)
-  {
-    spliceStart = oldLen - 1;
-  }
-  if (numRemoved > oldFullText.length - spliceStart - 1)
-  {
-    numRemoved = oldFullText.length - spliceStart - 1;
-  }
-  var oldText = oldFullText.substring(spliceStart, spliceStart + numRemoved);
-  var newLen = oldLen + newText.length - oldText.length;
-
-  var assem = Changeset.smartOpAssembler();
-  assem.appendOpWithText('=', oldFullText.substring(0, spliceStart));
-  assem.appendOpWithText('-', oldText);
-  assem.appendOpWithText('+', newText, optNewTextAPairs, pool);
-  assem.endDocument();
-  return Changeset.pack(oldLen, newLen, assem.toString(), newText);
-};
-
-Changeset.toSplices = function(cs)
-{
-  // get a list of splices, [startChar, endChar, newText]
-  var unpacked = Changeset.unpack(cs);
-  var splices = [];
-
-  var oldPos = 0;
-  var iter = Changeset.opIterator(unpacked.ops);
-  var charIter = Changeset.stringIterator(unpacked.charBank);
-  var inSplice = false;
-  while (iter.hasNext())
-  {
-    var op = iter.next();
-    if (op.opcode == '=')
-    {
-      oldPos += op.chars;
-      inSplice = false;
-    }
-    else
-    {
-      if (!inSplice)
-      {
-        splices.push([oldPos, oldPos, ""]);
-        inSplice = true;
-      }
-      if (op.opcode == '-')
-      {
-        oldPos += op.chars;
-        splices[splices.length - 1][1] += op.chars;
-      }
-      else if (op.opcode == '+')
-      {
-        splices[splices.length - 1][2] += charIter.take(op.chars);
-      }
-    }
-  }
-
-  return splices;
-};
-
-Changeset.characterRangeFollow = function(cs, startChar, endChar, insertionsAfter)
-{
-  var newStartChar = startChar;
-  var newEndChar = endChar;
-  var splices = Changeset.toSplices(cs);
-  var lengthChangeSoFar = 0;
-  for (var i = 0; i < splices.length; i++)
-  {
-    var splice = splices[i];
-    var spliceStart = splice[0] + lengthChangeSoFar;
-    var spliceEnd = splice[1] + lengthChangeSoFar;
-    var newTextLength = splice[2].length;
-    var thisLengthChange = newTextLength - (spliceEnd - spliceStart);
-
-    if (spliceStart <= newStartChar && spliceEnd >= newEndChar)
-    {
-      // splice fully replaces/deletes range
-      // (also case that handles insertion at a collapsed selection)
-      if (insertionsAfter)
-      {
-        newStartChar = newEndChar = spliceStart;
-      }
-      else
-      {
-        newStartChar = newEndChar = spliceStart + newTextLength;
-      }
-    }
-    else if (spliceEnd <= newStartChar)
-    {
-      // splice is before range
-      newStartChar += thisLengthChange;
-      newEndChar += thisLengthChange;
-    }
-    else if (spliceStart >= newEndChar)
-    {
-      // splice is after range
-    }
-    else if (spliceStart >= newStartChar && spliceEnd <= newEndChar)
-    {
-      // splice is inside range
-      newEndChar += thisLengthChange;
-    }
-    else if (spliceEnd < newEndChar)
-    {
-      // splice overlaps beginning of range
-      newStartChar = spliceStart + newTextLength;
-      newEndChar += thisLengthChange;
-    }
-    else
-    {
-      // splice overlaps end of range
-      newEndChar = spliceStart;
-    }
-
-    lengthChangeSoFar += thisLengthChange;
-  }
-
-  return [newStartChar, newEndChar];
-};
-
-Changeset.moveOpsToNewPool = function(cs, oldPool, newPool)
-{
-  // works on changeset or attribution string
-  var dollarPos = cs.indexOf('$');
-  if (dollarPos < 0)
-  {
-    dollarPos = cs.length;
-  }
-  var upToDollar = cs.substring(0, dollarPos);
-  var fromDollar = cs.substring(dollarPos);
-  // order of attribs stays the same
-  return upToDollar.replace(/\*([0-9a-z]+)/g, function(_, a)
-  {
-    var oldNum = Changeset.parseNum(a);
-    var pair = oldPool.getAttrib(oldNum);
-    var newNum = newPool.putAttrib(pair);
-    return '*' + Changeset.numToString(newNum);
-  }) + fromDollar;
-};
-
-Changeset.makeAttribution = function(text)
-{
-  var assem = Changeset.smartOpAssembler();
-  assem.appendOpWithText('+', text);
-  return assem.toString();
-};
-
-// callable on a changeset, attribution string, or attribs property of an op
-Changeset.eachAttribNumber = function(cs, func)
-{
-  var dollarPos = cs.indexOf('$');
-  if (dollarPos < 0)
-  {
-    dollarPos = cs.length;
-  }
-  var upToDollar = cs.substring(0, dollarPos);
-
-  upToDollar.replace(/\*([0-9a-z]+)/g, function(_, a)
-  {
-    func(Changeset.parseNum(a));
-    return '';
-  });
-};
-
-// callable on a changeset, attribution string, or attribs property of an op,
-// though it may easily create adjacent ops that can be merged.
-Changeset.filterAttribNumbers = function(cs, filter)
-{
-  return Changeset.mapAttribNumbers(cs, filter);
-};
-
-Changeset.mapAttribNumbers = function(cs, func)
-{
-  var dollarPos = cs.indexOf('$');
-  if (dollarPos < 0)
-  {
-    dollarPos = cs.length;
-  }
-  var upToDollar = cs.substring(0, dollarPos);
-
-  var newUpToDollar = upToDollar.replace(/\*([0-9a-z]+)/g, function(s, a)
-  {
-    var n = func(Changeset.parseNum(a));
-    if (n === true)
-    {
-      return s;
-    }
-    else if ((typeof n) === "number")
-    {
-      return '*' + Changeset.numToString(n);
-    }
-    else
-    {
-      return '';
-    }
-  });
-
-  return newUpToDollar + cs.substring(dollarPos);
-};
-
-Changeset.makeAText = function(text, attribs)
-{
-  return {
-    text: text,
-    attribs: (attribs || Changeset.makeAttribution(text))
-  };
-};
-
-Changeset.applyToAText = function(cs, atext, pool)
-{
-  return {
-    text: Changeset.applyToText(cs, atext.text),
-    attribs: Changeset.applyToAttribution(cs, atext.attribs, pool)
-  };
-};
-
-Changeset.cloneAText = function(atext)
-{
-  return {
-    text: atext.text,
-    attribs: atext.attribs
-  };
-};
-
-Changeset.copyAText = function(atext1, atext2)
-{
-  atext2.text = atext1.text;
-  atext2.attribs = atext1.attribs;
-};
-
-Changeset.appendATextToAssembler = function(atext, assem)
-{
-  // intentionally skips last newline char of atext
-  var iter = Changeset.opIterator(atext.attribs);
-  var op = Changeset.newOp();
-  while (iter.hasNext())
-  {
-    iter.next(op);
-    if (!iter.hasNext())
-    {
-      // last op, exclude final newline
-      if (op.lines <= 1)
-      {
-        op.lines = 0;
-        op.chars--;
-        if (op.chars)
-        {
-          assem.append(op);
-        }
-      }
-      else
-      {
-        var nextToLastNewlineEnd = atext.text.lastIndexOf('\n', atext.text.length - 2) + 1;
-        var lastLineLength = atext.text.length - nextToLastNewlineEnd - 1;
-        op.lines--;
-        op.chars -= (lastLineLength + 1);
-        assem.append(op);
-        op.lines = 0;
-        op.chars = lastLineLength;
-        if (op.chars)
-        {
-          assem.append(op);
-        }
-      }
-    }
-    else
-    {
-      assem.append(op);
-    }
-  }
-};
-
-Changeset.prepareForWire = function(cs, pool)
-{
-  var newPool = new AttribPool();
-  var newCs = Changeset.moveOpsToNewPool(cs, pool, newPool);
-  return {
-    translated: newCs,
-    pool: newPool
-  };
-};
-
-Changeset.isIdentity = function(cs)
-{
-  var unpacked = Changeset.unpack(cs);
-  return unpacked.ops == "" && unpacked.oldLen == unpacked.newLen;
-};
-
-Changeset.opAttributeValue = function(op, key, pool)
-{
-  return Changeset.attribsAttributeValue(op.attribs, key, pool);
-};
-
-Changeset.attribsAttributeValue = function(attribs, key, pool)
-{
-  var value = '';
-  if (attribs)
-  {
-    Changeset.eachAttribNumber(attribs, function(n)
-    {
-      if (pool.getAttribKey(n) == key)
-      {
-        value = pool.getAttribValue(n);
-      }
-    });
-  }
-  return value;
-};
-
-Changeset.builder = function(oldLen)
-{
-  var assem = Changeset.smartOpAssembler();
-  var o = Changeset.newOp();
-  var charBank = Changeset.stringAssembler();
-
-  var self = {
-    // attribs are [[key1,value1],[key2,value2],...] or '*0*1...' (no pool needed in latter case)
-    keep: function(N, L, attribs, pool)
-    {
-      o.opcode = '=';
-      o.attribs = (attribs && Changeset.makeAttribsString('=', attribs, pool)) || '';
-      o.chars = N;
-      o.lines = (L || 0);
-      assem.append(o);
-      return self;
-    },
-    keepText: function(text, attribs, pool)
-    {
-      assem.appendOpWithText('=', text, attribs, pool);
-      return self;
-    },
-    insert: function(text, attribs, pool)
-    {
-      assem.appendOpWithText('+', text, attribs, pool);
-      charBank.append(text);
-      return self;
-    },
-    remove: function(N, L)
-    {
-      o.opcode = '-';
-      o.attribs = '';
-      o.chars = N;
-      o.lines = (L || 0);
-      assem.append(o);
-      return self;
-    },
-    toString: function()
-    {
-      assem.endDocument();
-      var newLen = oldLen + assem.getLengthChange();
-      return Changeset.pack(oldLen, newLen, assem.toString(), charBank.toString());
-    }
-  };
-
-  return self;
-};
-
-Changeset.makeAttribsString = function(opcode, attribs, pool)
-{
-  // makeAttribsString(opcode, '*3') or makeAttribsString(opcode, [['foo','bar']], myPool) work
-  if (!attribs)
-  {
-    return '';
-  }
-  else if ((typeof attribs) == "string")
-  {
-    return attribs;
-  }
-  else if (pool && attribs && attribs.length)
-  {
-    if (attribs.length > 1)
-    {
-      attribs = attribs.slice();
-      attribs.sort();
-    }
-    var result = [];
-    for (var i = 0; i < attribs.length; i++)
-    {
-      var pair = attribs[i];
-      if (opcode == '=' || (opcode == '+' && pair[1]))
-      {
-        result.push('*' + Changeset.numToString(pool.putAttrib(pair)));
-      }
-    }
-    return result.join('');
-  }
-};
-
-// like "substring" but on a single-line attribution string
-Changeset.subattribution = function(astr, start, optEnd)
-{
-  var iter = Changeset.opIterator(astr, 0);
-  var assem = Changeset.smartOpAssembler();
-  var attOp = Changeset.newOp();
-  var csOp = Changeset.newOp();
-  var opOut = Changeset.newOp();
-
-  function doCsOp()
-  {
-    if (csOp.chars)
-    {
-      while (csOp.opcode && (attOp.opcode || iter.hasNext()))
-      {
-        if (!attOp.opcode) iter.next(attOp);
-
-        if (csOp.opcode && attOp.opcode && csOp.chars >= attOp.chars && attOp.lines > 0 && csOp.lines <= 0)
-        {
-          csOp.lines++;
-        }
-
-        Changeset._slicerZipperFunc(attOp, csOp, opOut, null);
-        if (opOut.opcode)
-        {
-          assem.append(opOut);
-          opOut.opcode = '';
-        }
-      }
-    }
-  }
-
-  csOp.opcode = '-';
-  csOp.chars = start;
-
-  doCsOp();
-
-  if (optEnd === undefined)
-  {
-    if (attOp.opcode)
-    {
-      assem.append(attOp);
-    }
-    while (iter.hasNext())
-    {
-      iter.next(attOp);
-      assem.append(attOp);
-    }
-  }
-  else
-  {
-    csOp.opcode = '=';
-    csOp.chars = optEnd - start;
-    doCsOp();
-  }
-
-  return assem.toString();
-};
-
-Changeset.inverse = function(cs, lines, alines, pool)
-{
-  // lines and alines are what the changeset is meant to apply to.
-  // They may be arrays or objects with .get(i) and .length methods.
-  // They include final newlines on lines.
-
-
-  function lines_get(idx)
-  {
-    if (lines.get)
-    {
-      return lines.get(idx);
-    }
-    else
-    {
-      return lines[idx];
-    }
-  }
-
-  function lines_length()
-  {
-    if ((typeof lines.length) == "number")
-    {
-      return lines.length;
-    }
-    else
-    {
-      return lines.length();
-    }
-  }
-
-  function alines_get(idx)
-  {
-    if (alines.get)
-    {
-      return alines.get(idx);
-    }
-    else
-    {
-      return alines[idx];
-    }
-  }
-
-  function alines_length()
-  {
-    if ((typeof alines.length) == "number")
-    {
-      return alines.length;
-    }
-    else
-    {
-      return alines.length();
-    }
-  }
-
-  var curLine = 0;
-  var curChar = 0;
-  var curLineOpIter = null;
-  var curLineOpIterLine;
-  var curLineNextOp = Changeset.newOp('+');
-
-  var unpacked = Changeset.unpack(cs);
-  var csIter = Changeset.opIterator(unpacked.ops);
-  var builder = Changeset.builder(unpacked.newLen);
-
-  function consumeAttribRuns(numChars, func /*(len, attribs, endsLine)*/ )
-  {
-
-    if ((!curLineOpIter) || (curLineOpIterLine != curLine))
-    {
-      // create curLineOpIter and advance it to curChar
-      curLineOpIter = Changeset.opIterator(alines_get(curLine));
-      curLineOpIterLine = curLine;
-      var indexIntoLine = 0;
-      var done = false;
-      while (!done)
-      {
-        curLineOpIter.next(curLineNextOp);
-        if (indexIntoLine + curLineNextOp.chars >= curChar)
-        {
-          curLineNextOp.chars -= (curChar - indexIntoLine);
-          done = true;
-        }
-        else
-        {
-          indexIntoLine += curLineNextOp.chars;
-        }
-      }
-    }
-
-    while (numChars > 0)
-    {
-      if ((!curLineNextOp.chars) && (!curLineOpIter.hasNext()))
-      {
-        curLine++;
-        curChar = 0;
-        curLineOpIterLine = curLine;
-        curLineNextOp.chars = 0;
-        curLineOpIter = Changeset.opIterator(alines_get(curLine));
-      }
-      if (!curLineNextOp.chars)
-      {
-        curLineOpIter.next(curLineNextOp);
-      }
-      var charsToUse = Math.min(numChars, curLineNextOp.chars);
-      func(charsToUse, curLineNextOp.attribs, charsToUse == curLineNextOp.chars && curLineNextOp.lines > 0);
-      numChars -= charsToUse;
-      curLineNextOp.chars -= charsToUse;
-      curChar += charsToUse;
-    }
-
-    if ((!curLineNextOp.chars) && (!curLineOpIter.hasNext()))
-    {
-      curLine++;
-      curChar = 0;
-    }
-  }
-
-  function skip(N, L)
-  {
-    if (L)
-    {
-      curLine += L;
-      curChar = 0;
-    }
-    else
-    {
-      if (curLineOpIter && curLineOpIterLine == curLine)
-      {
-        consumeAttribRuns(N, function()
-        {});
-      }
-      else
-      {
-        curChar += N;
-      }
-    }
-  }
-
-  function nextText(numChars)
-  {
-    var len = 0;
-    var assem = Changeset.stringAssembler();
-    var firstString = lines_get(curLine).substring(curChar);
-    len += firstString.length;
-    assem.append(firstString);
-
-    var lineNum = curLine + 1;
-    while (len < numChars)
-    {
-      var nextString = lines_get(lineNum);
-      len += nextString.length;
-      assem.append(nextString);
-      lineNum++;
-    }
-
-    return assem.toString().substring(0, numChars);
-  }
-
-  function cachedStrFunc(func)
-  {
-    var cache = {};
-    return function(s)
-    {
-      if (!cache[s])
-      {
-        cache[s] = func(s);
-      }
-      return cache[s];
-    };
-  }
-
-  var attribKeys = [];
-  var attribValues = [];
-  while (csIter.hasNext())
-  {
-    var csOp = csIter.next();
-    if (csOp.opcode == '=')
-    {
-      if (csOp.attribs)
-      {
-        attribKeys.length = 0;
-        attribValues.length = 0;
-        Changeset.eachAttribNumber(csOp.attribs, function(n)
-        {
-          attribKeys.push(pool.getAttribKey(n));
-          attribValues.push(pool.getAttribValue(n));
-        });
-        var undoBackToAttribs = cachedStrFunc(function(attribs)
-        {
-          var backAttribs = [];
-          for (var i = 0; i < attribKeys.length; i++)
-          {
-            var appliedKey = attribKeys[i];
-            var appliedValue = attribValues[i];
-            var oldValue = Changeset.attribsAttributeValue(attribs, appliedKey, pool);
-            if (appliedValue != oldValue)
-            {
-              backAttribs.push([appliedKey, oldValue]);
-            }
-          }
-          return Changeset.makeAttribsString('=', backAttribs, pool);
-        });
-        consumeAttribRuns(csOp.chars, function(len, attribs, endsLine)
-        {
-          builder.keep(len, endsLine ? 1 : 0, undoBackToAttribs(attribs));
-        });
-      }
-      else
-      {
-        skip(csOp.chars, csOp.lines);
-        builder.keep(csOp.chars, csOp.lines);
-      }
-    }
-    else if (csOp.opcode == '+')
-    {
-      builder.remove(csOp.chars, csOp.lines);
-    }
-    else if (csOp.opcode == '-')
-    {
-      var textBank = nextText(csOp.chars);
-      var textBankIndex = 0;
-      consumeAttribRuns(csOp.chars, function(len, attribs, endsLine)
-      {
-        builder.insert(textBank.substr(textBankIndex, len), attribs);
-        textBankIndex += len;
-      });
-    }
-  }
-
-  return Changeset.checkRep(builder.toString());
-};
-
-// %CLIENT FILE ENDS HERE%
-Changeset.follow = function(cs1, cs2, reverseInsertOrder, pool)
-{
-  var unpacked1 = Changeset.unpack(cs1);
-  var unpacked2 = Changeset.unpack(cs2);
-  var len1 = unpacked1.oldLen;
-  var len2 = unpacked2.oldLen;
-  Changeset.assert(len1 == len2, "mismatched follow");
-  var chars1 = Changeset.stringIterator(unpacked1.charBank);
-  var chars2 = Changeset.stringIterator(unpacked2.charBank);
-
-  var oldLen = unpacked1.newLen;
-  var oldPos = 0;
-  var newLen = 0;
-
-  var hasInsertFirst = Changeset.attributeTester(['insertorder', 'first'], pool);
-
-  var newOps = Changeset.applyZip(unpacked1.ops, 0, unpacked2.ops, 0, function(op1, op2, opOut)
-  {
-    if (op1.opcode == '+' || op2.opcode == '+')
-    {
-      var whichToDo;
-      if (op2.opcode != '+')
-      {
-        whichToDo = 1;
-      }
-      else if (op1.opcode != '+')
-      {
-        whichToDo = 2;
-      }
-      else
-      {
-        // both +
-        var firstChar1 = chars1.peek(1);
-        var firstChar2 = chars2.peek(1);
-        var insertFirst1 = hasInsertFirst(op1.attribs);
-        var insertFirst2 = hasInsertFirst(op2.attribs);
-        if (insertFirst1 && !insertFirst2)
-        {
-          whichToDo = 1;
-        }
-        else if (insertFirst2 && !insertFirst1)
-        {
-          whichToDo = 2;
-        }
-        // insert string that doesn't start with a newline first so as not to break up lines
-        else if (firstChar1 == '\n' && firstChar2 != '\n')
-        {
-          whichToDo = 2;
-        }
-        else if (firstChar1 != '\n' && firstChar2 == '\n')
-        {
-          whichToDo = 1;
-        }
-        // break symmetry:
-        else if (reverseInsertOrder)
-        {
-          whichToDo = 2;
-        }
-        else
-        {
-          whichToDo = 1;
-        }
-      }
-      if (whichToDo == 1)
-      {
-        chars1.skip(op1.chars);
-        opOut.opcode = '=';
-        opOut.lines = op1.lines;
-        opOut.chars = op1.chars;
-        opOut.attribs = '';
-        op1.opcode = '';
-      }
-      else
-      {
-        // whichToDo == 2
-        chars2.skip(op2.chars);
-        Changeset.copyOp(op2, opOut);
-        op2.opcode = '';
-      }
-    }
-    else if (op1.opcode == '-')
-    {
-      if (!op2.opcode)
-      {
-        op1.opcode = '';
-      }
-      else
-      {
-        if (op1.chars <= op2.chars)
-        {
-          op2.chars -= op1.chars;
-          op2.lines -= op1.lines;
-          op1.opcode = '';
-          if (!op2.chars)
-          {
-            op2.opcode = '';
-          }
-        }
-        else
-        {
-          op1.chars -= op2.chars;
-          op1.lines -= op2.lines;
-          op2.opcode = '';
-        }
-      }
-    }
-    else if (op2.opcode == '-')
-    {
-      Changeset.copyOp(op2, opOut);
-      if (!op1.opcode)
-      {
-        op2.opcode = '';
-      }
-      else if (op2.chars <= op1.chars)
-      {
-        // delete part or all of a keep
-        op1.chars -= op2.chars;
-        op1.lines -= op2.lines;
-        op2.opcode = '';
-        if (!op1.chars)
-        {
-          op1.opcode = '';
-        }
-      }
-      else
-      {
-        // delete all of a keep, and keep going
-        opOut.lines = op1.lines;
-        opOut.chars = op1.chars;
-        op2.lines -= op1.lines;
-        op2.chars -= op1.chars;
-        op1.opcode = '';
-      }
-    }
-    else if (!op1.opcode)
-    {
-      Changeset.copyOp(op2, opOut);
-      op2.opcode = '';
-    }
-    else if (!op2.opcode)
-    {
-      Changeset.copyOp(op1, opOut);
-      op1.opcode = '';
-    }
-    else
-    {
-      // both keeps
-      opOut.opcode = '=';
-      opOut.attribs = Changeset.followAttributes(op1.attribs, op2.attribs, pool);
-      if (op1.chars <= op2.chars)
-      {
-        opOut.chars = op1.chars;
-        opOut.lines = op1.lines;
-        op2.chars -= op1.chars;
-        op2.lines -= op1.lines;
-        op1.opcode = '';
-        if (!op2.chars)
-        {
-          op2.opcode = '';
-        }
-      }
-      else
-      {
-        opOut.chars = op2.chars;
-        opOut.lines = op2.lines;
-        op1.chars -= op2.chars;
-        op1.lines -= op2.lines;
-        op2.opcode = '';
-      }
-    }
-    switch (opOut.opcode)
-    {
-    case '=':
-      oldPos += opOut.chars;
-      newLen += opOut.chars;
-      break;
-    case '-':
-      oldPos += opOut.chars;
-      break;
-    case '+':
-      newLen += opOut.chars;
-      break;
-    }
-  });
-  newLen += oldLen - oldPos;
-
-  return Changeset.pack(oldLen, newLen, newOps, unpacked2.charBank);
-};
-
-Changeset.followAttributes = function(att1, att2, pool)
-{
-  // The merge of two sets of attribute changes to the same text
-  // takes the lexically-earlier value if there are two values
-  // for the same key.  Otherwise, all key/value changes from
-  // both attribute sets are taken.  This operation is the "follow",
-  // so a set of changes is produced that can be applied to att1
-  // to produce the merged set.
-  if ((!att2) || (!pool)) return '';
-  if (!att1) return att2;
-  var atts = [];
-  att2.replace(/\*([0-9a-z]+)/g, function(_, a)
-  {
-    atts.push(pool.getAttrib(Changeset.parseNum(a)));
-    return '';
-  });
-  att1.replace(/\*([0-9a-z]+)/g, function(_, a)
-  {
-    var pair1 = pool.getAttrib(Changeset.parseNum(a));
-    for (var i = 0; i < atts.length; i++)
-    {
-      var pair2 = atts[i];
-      if (pair1[0] == pair2[0])
-      {
-        if (pair1[1] <= pair2[1])
-        {
-          // winner of merge is pair1, delete this attribute
-          atts.splice(i, 1);
-        }
-        break;
-      }
-    }
-    return '';
-  });
-  // we've only removed attributes, so they're already sorted
-  var buf = Changeset.stringAssembler();
-  for (var i = 0; i < atts.length; i++)
-  {
-    buf.append('*');
-    buf.append(Changeset.numToString(pool.putAttrib(atts[i])));
-  }
-  return buf.toString();
-};
-
-exports.Changeset = Changeset;
-exports.AttribPool = AttribPool;
diff --git a/static/js/easysync2_client.js b/static/js/easysync2_client.js
deleted file mode 100644
index f4f3d08fb..000000000
--- a/static/js/easysync2_client.js
+++ /dev/null
@@ -1,2274 +0,0 @@
-/**
- * This code is mostly from the old Etherpad. Please help us to comment this code. 
- * This helps other people to understand this code better and helps them to improve it.
- * TL;DR COMMENTS ON THIS FILE ARE HIGHLY APPRECIATED
- */
-
-// DO NOT EDIT THIS FILE, edit infrastructure/ace/www/easysync2.js
-// THIS FILE IS ALSO AN APPJET MODULE: etherpad.collab.ace.easysync2
-/**
- * Copyright 2009 Google Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS-IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-//var _opt = (this.Easysync2Support || null);
-var _opt = null; // disable optimization for now
-
-function AttribPool()
-{
-  var p = {};
-  p.numToAttrib = {}; // e.g. {0: ['foo','bar']}
-  p.attribToNum = {}; // e.g. {'foo,bar': 0}
-  p.nextNum = 0;
-
-  p.putAttrib = function(attrib, dontAddIfAbsent)
-  {
-    var str = String(attrib);
-    if (str in p.attribToNum)
-    {
-      return p.attribToNum[str];
-    }
-    if (dontAddIfAbsent)
-    {
-      return -1;
-    }
-    var num = p.nextNum++;
-    p.attribToNum[str] = num;
-    p.numToAttrib[num] = [String(attrib[0] || ''), String(attrib[1] || '')];
-    return num;
-  };
-
-  p.getAttrib = function(num)
-  {
-    var pair = p.numToAttrib[num];
-    if (!pair) return pair;
-    return [pair[0], pair[1]]; // return a mutable copy
-  };
-
-  p.getAttribKey = function(num)
-  {
-    var pair = p.numToAttrib[num];
-    if (!pair) return '';
-    return pair[0];
-  };
-
-  p.getAttribValue = function(num)
-  {
-    var pair = p.numToAttrib[num];
-    if (!pair) return '';
-    return pair[1];
-  };
-
-  p.eachAttrib = function(func)
-  {
-    for (var n in p.numToAttrib)
-    {
-      var pair = p.numToAttrib[n];
-      func(pair[0], pair[1]);
-    }
-  };
-
-  p.toJsonable = function()
-  {
-    return {
-      numToAttrib: p.numToAttrib,
-      nextNum: p.nextNum
-    };
-  };
-
-  p.fromJsonable = function(obj)
-  {
-    p.numToAttrib = obj.numToAttrib;
-    p.nextNum = obj.nextNum;
-    p.attribToNum = {};
-    for (var n in p.numToAttrib)
-    {
-      p.attribToNum[String(p.numToAttrib[n])] = Number(n);
-    }
-    return p;
-  };
-
-  return p;
-}
-
-var Changeset = {};
-
-Changeset.error = function error(msg)
-{
-  var e = new Error(msg);
-  e.easysync = true;
-  throw e;
-};
-Changeset.assert = function assert(b, msgParts)
-{
-  if (!b)
-  {
-    var msg = Array.prototype.slice.call(arguments, 1).join('');
-    Changeset.error("Changeset: " + msg);
-  }
-};
-
-Changeset.parseNum = function(str)
-{
-  return parseInt(str, 36);
-};
-Changeset.numToString = function(num)
-{
-  return num.toString(36).toLowerCase();
-};
-Changeset.toBaseTen = function(cs)
-{
-  var dollarIndex = cs.indexOf('$');
-  var beforeDollar = cs.substring(0, dollarIndex);
-  var fromDollar = cs.substring(dollarIndex);
-  return beforeDollar.replace(/[0-9a-z]+/g, function(s)
-  {
-    return String(Changeset.parseNum(s));
-  }) + fromDollar;
-};
-
-Changeset.oldLen = function(cs)
-{
-  return Changeset.unpack(cs).oldLen;
-};
-Changeset.newLen = function(cs)
-{
-  return Changeset.unpack(cs).newLen;
-};
-
-Changeset.opIterator = function(opsStr, optStartIndex)
-{
-  //print(opsStr);
-  var regex = /((?:\*[0-9a-z]+)*)(?:\|([0-9a-z]+))?([-+=])([0-9a-z]+)|\?|/g;
-  var startIndex = (optStartIndex || 0);
-  var curIndex = startIndex;
-  var prevIndex = curIndex;
-
-  function nextRegexMatch()
-  {
-    prevIndex = curIndex;
-    var result;
-    if (_opt)
-    {
-      result = _opt.nextOpInString(opsStr, curIndex);
-      if (result)
-      {
-        if (result.opcode() == '?')
-        {
-          Changeset.error("Hit error opcode in op stream");
-        }
-        curIndex = result.lastIndex();
-      }
-    }
-    else
-    {
-      regex.lastIndex = curIndex;
-      result = regex.exec(opsStr);
-      curIndex = regex.lastIndex;
-      if (result[0] == '?')
-      {
-        Changeset.error("Hit error opcode in op stream");
-      }
-    }
-    return result;
-  }
-  var regexResult = nextRegexMatch();
-  var obj = Changeset.newOp();
-
-  function next(optObj)
-  {
-    var op = (optObj || obj);
-    if (_opt && regexResult)
-    {
-      op.attribs = regexResult.attribs();
-      op.lines = regexResult.lines();
-      op.chars = regexResult.chars();
-      op.opcode = regexResult.opcode();
-      regexResult = nextRegexMatch();
-    }
-    else if ((!_opt) && regexResult[0])
-    {
-      op.attribs = regexResult[1];
-      op.lines = Changeset.parseNum(regexResult[2] || 0);
-      op.opcode = regexResult[3];
-      op.chars = Changeset.parseNum(regexResult[4]);
-      regexResult = nextRegexMatch();
-    }
-    else
-    {
-      Changeset.clearOp(op);
-    }
-    return op;
-  }
-
-  function hasNext()
-  {
-    return !!(_opt ? regexResult : regexResult[0]);
-  }
-
-  function lastIndex()
-  {
-    return prevIndex;
-  }
-  return {
-    next: next,
-    hasNext: hasNext,
-    lastIndex: lastIndex
-  };
-};
-
-Changeset.clearOp = function(op)
-{
-  op.opcode = '';
-  op.chars = 0;
-  op.lines = 0;
-  op.attribs = '';
-};
-Changeset.newOp = function(optOpcode)
-{
-  return {
-    opcode: (optOpcode || ''),
-    chars: 0,
-    lines: 0,
-    attribs: ''
-  };
-};
-Changeset.cloneOp = function(op)
-{
-  return {
-    opcode: op.opcode,
-    chars: op.chars,
-    lines: op.lines,
-    attribs: op.attribs
-  };
-};
-Changeset.copyOp = function(op1, op2)
-{
-  op2.opcode = op1.opcode;
-  op2.chars = op1.chars;
-  op2.lines = op1.lines;
-  op2.attribs = op1.attribs;
-};
-Changeset.opString = function(op)
-{
-  // just for debugging
-  if (!op.opcode) return 'null';
-  var assem = Changeset.opAssembler();
-  assem.append(op);
-  return assem.toString();
-};
-Changeset.stringOp = function(str)
-{
-  // just for debugging
-  return Changeset.opIterator(str).next();
-};
-
-Changeset.checkRep = function(cs)
-{
-  // doesn't check things that require access to attrib pool (e.g. attribute order)
-  // or original string (e.g. newline positions)
-  var unpacked = Changeset.unpack(cs);
-  var oldLen = unpacked.oldLen;
-  var newLen = unpacked.newLen;
-  var ops = unpacked.ops;
-  var charBank = unpacked.charBank;
-
-  var assem = Changeset.smartOpAssembler();
-  var oldPos = 0;
-  var calcNewLen = 0;
-  var numInserted = 0;
-  var iter = Changeset.opIterator(ops);
-  while (iter.hasNext())
-  {
-    var o = iter.next();
-    switch (o.opcode)
-    {
-    case '=':
-      oldPos += o.chars;
-      calcNewLen += o.chars;
-      break;
-    case '-':
-      oldPos += o.chars;
-      Changeset.assert(oldPos < oldLen, oldPos, " >= ", oldLen, " in ", cs);
-      break;
-    case '+':
-      {
-        calcNewLen += o.chars;
-        numInserted += o.chars;
-        Changeset.assert(calcNewLen < newLen, calcNewLen, " >= ", newLen, " in ", cs);
-        break;
-      }
-    }
-    assem.append(o);
-  }
-
-  calcNewLen += oldLen - oldPos;
-  charBank = charBank.substring(0, numInserted);
-  while (charBank.length < numInserted)
-  {
-    charBank += "?";
-  }
-
-  assem.endDocument();
-  var normalized = Changeset.pack(oldLen, calcNewLen, assem.toString(), charBank);
-  Changeset.assert(normalized == cs, normalized, ' != ', cs);
-
-  return cs;
-}
-
-Changeset.smartOpAssembler = function()
-{
-  // Like opAssembler but able to produce conforming changesets
-  // from slightly looser input, at the cost of speed.
-  // Specifically:
-  // - merges consecutive operations that can be merged
-  // - strips final "="
-  // - ignores 0-length changes
-  // - reorders consecutive + and - (which margingOpAssembler doesn't do)
-  var minusAssem = Changeset.mergingOpAssembler();
-  var plusAssem = Changeset.mergingOpAssembler();
-  var keepAssem = Changeset.mergingOpAssembler();
-  var assem = Changeset.stringAssembler();
-  var lastOpcode = '';
-  var lengthChange = 0;
-
-  function flushKeeps()
-  {
-    assem.append(keepAssem.toString());
-    keepAssem.clear();
-  }
-
-  function flushPlusMinus()
-  {
-    assem.append(minusAssem.toString());
-    minusAssem.clear();
-    assem.append(plusAssem.toString());
-    plusAssem.clear();
-  }
-
-  function append(op)
-  {
-    if (!op.opcode) return;
-    if (!op.chars) return;
-
-    if (op.opcode == '-')
-    {
-      if (lastOpcode == '=')
-      {
-        flushKeeps();
-      }
-      minusAssem.append(op);
-      lengthChange -= op.chars;
-    }
-    else if (op.opcode == '+')
-    {
-      if (lastOpcode == '=')
-      {
-        flushKeeps();
-      }
-      plusAssem.append(op);
-      lengthChange += op.chars;
-    }
-    else if (op.opcode == '=')
-    {
-      if (lastOpcode != '=')
-      {
-        flushPlusMinus();
-      }
-      keepAssem.append(op);
-    }
-    lastOpcode = op.opcode;
-  }
-
-  function appendOpWithText(opcode, text, attribs, pool)
-  {
-    var op = Changeset.newOp(opcode);
-    op.attribs = Changeset.makeAttribsString(opcode, attribs, pool);
-    var lastNewlinePos = text.lastIndexOf('\n');
-    if (lastNewlinePos < 0)
-    {
-      op.chars = text.length;
-      op.lines = 0;
-      append(op);
-    }
-    else
-    {
-      op.chars = lastNewlinePos + 1;
-      op.lines = text.match(/\n/g).length;
-      append(op);
-      op.chars = text.length - (lastNewlinePos + 1);
-      op.lines = 0;
-      append(op);
-    }
-  }
-
-  function toString()
-  {
-    flushPlusMinus();
-    flushKeeps();
-    return assem.toString();
-  }
-
-  function clear()
-  {
-    minusAssem.clear();
-    plusAssem.clear();
-    keepAssem.clear();
-    assem.clear();
-    lengthChange = 0;
-  }
-
-  function endDocument()
-  {
-    keepAssem.endDocument();
-  }
-
-  function getLengthChange()
-  {
-    return lengthChange;
-  }
-
-  return {
-    append: append,
-    toString: toString,
-    clear: clear,
-    endDocument: endDocument,
-    appendOpWithText: appendOpWithText,
-    getLengthChange: getLengthChange
-  };
-};
-
-if (_opt)
-{
-  Changeset.mergingOpAssembler = function()
-  {
-    var assem = _opt.mergingOpAssembler();
-
-    function append(op)
-    {
-      assem.append(op.opcode, op.chars, op.lines, op.attribs);
-    }
-
-    function toString()
-    {
-      return assem.toString();
-    }
-
-    function clear()
-    {
-      assem.clear();
-    }
-
-    function endDocument()
-    {
-      assem.endDocument();
-    }
-
-    return {
-      append: append,
-      toString: toString,
-      clear: clear,
-      endDocument: endDocument
-    };
-  };
-}
-else
-{
-  Changeset.mergingOpAssembler = function()
-  {
-    // This assembler can be used in production; it efficiently
-    // merges consecutive operations that are mergeable, ignores
-    // no-ops, and drops final pure "keeps".  It does not re-order
-    // operations.
-    var assem = Changeset.opAssembler();
-    var bufOp = Changeset.newOp();
-
-    // If we get, for example, insertions [xxx\n,yyy], those don't merge,
-    // but if we get [xxx\n,yyy,zzz\n], that merges to [xxx\nyyyzzz\n].
-    // This variable stores the length of yyy and any other newline-less
-    // ops immediately after it.
-    var bufOpAdditionalCharsAfterNewline = 0;
-
-    function flush(isEndDocument)
-    {
-      if (bufOp.opcode)
-      {
-        if (isEndDocument && bufOp.opcode == '=' && !bufOp.attribs)
-        {
-          // final merged keep, leave it implicit
-        }
-        else
-        {
-          assem.append(bufOp);
-          if (bufOpAdditionalCharsAfterNewline)
-          {
-            bufOp.chars = bufOpAdditionalCharsAfterNewline;
-            bufOp.lines = 0;
-            assem.append(bufOp);
-            bufOpAdditionalCharsAfterNewline = 0;
-          }
-        }
-        bufOp.opcode = '';
-      }
-    }
-
-    function append(op)
-    {
-      if (op.chars > 0)
-      {
-        if (bufOp.opcode == op.opcode && bufOp.attribs == op.attribs)
-        {
-          if (op.lines > 0)
-          {
-            // bufOp and additional chars are all mergeable into a multi-line op
-            bufOp.chars += bufOpAdditionalCharsAfterNewline + op.chars;
-            bufOp.lines += op.lines;
-            bufOpAdditionalCharsAfterNewline = 0;
-          }
-          else if (bufOp.lines == 0)
-          {
-            // both bufOp and op are in-line
-            bufOp.chars += op.chars;
-          }
-          else
-          {
-            // append in-line text to multi-line bufOp
-            bufOpAdditionalCharsAfterNewline += op.chars;
-          }
-        }
-        else
-        {
-          flush();
-          Changeset.copyOp(op, bufOp);
-        }
-      }
-    }
-
-    function endDocument()
-    {
-      flush(true);
-    }
-
-    function toString()
-    {
-      flush();
-      return assem.toString();
-    }
-
-    function clear()
-    {
-      assem.clear();
-      Changeset.clearOp(bufOp);
-    }
-    return {
-      append: append,
-      toString: toString,
-      clear: clear,
-      endDocument: endDocument
-    };
-  };
-}
-
-if (_opt)
-{
-  Changeset.opAssembler = function()
-  {
-    var assem = _opt.opAssembler();
-    // this function allows op to be mutated later (doesn't keep a ref)
-
-    function append(op)
-    {
-      assem.append(op.opcode, op.chars, op.lines, op.attribs);
-    }
-
-    function toString()
-    {
-      return assem.toString();
-    }
-
-    function clear()
-    {
-      assem.clear();
-    }
-    return {
-      append: append,
-      toString: toString,
-      clear: clear
-    };
-  };
-}
-else
-{
-  Changeset.opAssembler = function()
-  {
-    var pieces = [];
-    // this function allows op to be mutated later (doesn't keep a ref)
-
-    function append(op)
-    {
-      pieces.push(op.attribs);
-      if (op.lines)
-      {
-        pieces.push('|', Changeset.numToString(op.lines));
-      }
-      pieces.push(op.opcode);
-      pieces.push(Changeset.numToString(op.chars));
-    }
-
-    function toString()
-    {
-      return pieces.join('');
-    }
-
-    function clear()
-    {
-      pieces.length = 0;
-    }
-    return {
-      append: append,
-      toString: toString,
-      clear: clear
-    };
-  };
-}
-
-Changeset.stringIterator = function(str)
-{
-  var curIndex = 0;
-
-  function assertRemaining(n)
-  {
-    Changeset.assert(n <= remaining(), "!(", n, " <= ", remaining(), ")");
-  }
-
-  function take(n)
-  {
-    assertRemaining(n);
-    var s = str.substr(curIndex, n);
-    curIndex += n;
-    return s;
-  }
-
-  function peek(n)
-  {
-    assertRemaining(n);
-    var s = str.substr(curIndex, n);
-    return s;
-  }
-
-  function skip(n)
-  {
-    assertRemaining(n);
-    curIndex += n;
-  }
-
-  function remaining()
-  {
-    return str.length - curIndex;
-  }
-  return {
-    take: take,
-    skip: skip,
-    remaining: remaining,
-    peek: peek
-  };
-};
-
-Changeset.stringAssembler = function()
-{
-  var pieces = [];
-
-  function append(x)
-  {
-    pieces.push(String(x));
-  }
-
-  function toString()
-  {
-    return pieces.join('');
-  }
-  return {
-    append: append,
-    toString: toString
-  };
-};
-
-// "lines" need not be an array as long as it supports certain calls (lines_foo inside).
-Changeset.textLinesMutator = function(lines)
-{
-  // Mutates lines, an array of strings, in place.
-  // Mutation operations have the same constraints as changeset operations
-  // with respect to newlines, but not the other additional constraints
-  // (i.e. ins/del ordering, forbidden no-ops, non-mergeability, final newline).
-  // Can be used to mutate lists of strings where the last char of each string
-  // is not actually a newline, but for the purposes of N and L values,
-  // the caller should pretend it is, and for things to work right in that case, the input
-  // to insert() should be a single line with no newlines.
-  var curSplice = [0, 0];
-  var inSplice = false;
-  // position in document after curSplice is applied:
-  var curLine = 0,
-      curCol = 0;
-  // invariant: if (inSplice) then (curLine is in curSplice[0] + curSplice.length - {2,3}) &&
-  //            curLine >= curSplice[0]
-  // invariant: if (inSplice && (curLine >= curSplice[0] + curSplice.length - 2)) then
-  //            curCol == 0
-
-  function lines_applySplice(s)
-  {
-    lines.splice.apply(lines, s);
-  }
-
-  function lines_toSource()
-  {
-    return lines.toSource();
-  }
-
-  function lines_get(idx)
-  {
-    if (lines.get)
-    {
-      return lines.get(idx);
-    }
-    else
-    {
-      return lines[idx];
-    }
-  }
-  // can be unimplemented if removeLines's return value not needed
-
-  function lines_slice(start, end)
-  {
-    if (lines.slice)
-    {
-      return lines.slice(start, end);
-    }
-    else
-    {
-      return [];
-    }
-  }
-
-  function lines_length()
-  {
-    if ((typeof lines.length) == "number")
-    {
-      return lines.length;
-    }
-    else
-    {
-      return lines.length();
-    }
-  }
-
-  function enterSplice()
-  {
-    curSplice[0] = curLine;
-    curSplice[1] = 0;
-    if (curCol > 0)
-    {
-      putCurLineInSplice();
-    }
-    inSplice = true;
-  }
-
-  function leaveSplice()
-  {
-    lines_applySplice(curSplice);
-    curSplice.length = 2;
-    curSplice[0] = curSplice[1] = 0;
-    inSplice = false;
-  }
-
-  function isCurLineInSplice()
-  {
-    return (curLine - curSplice[0] < (curSplice.length - 2));
-  }
-
-  function debugPrint(typ)
-  {
-    print(typ + ": " + curSplice.toSource() + " / " + curLine + "," + curCol + " / " + lines_toSource());
-  }
-
-  function putCurLineInSplice()
-  {
-    if (!isCurLineInSplice())
-    {
-      curSplice.push(lines_get(curSplice[0] + curSplice[1]));
-      curSplice[1]++;
-    }
-    return 2 + curLine - curSplice[0];
-  }
-
-  function skipLines(L, includeInSplice)
-  {
-    if (L)
-    {
-      if (includeInSplice)
-      {
-        if (!inSplice)
-        {
-          enterSplice();
-        }
-        for (var i = 0; i < L; i++)
-        {
-          curCol = 0;
-          putCurLineInSplice();
-          curLine++;
-        }
-      }
-      else
-      {
-        if (inSplice)
-        {
-          if (L > 1)
-          {
-            leaveSplice();
-          }
-          else
-          {
-            putCurLineInSplice();
-          }
-        }
-        curLine += L;
-        curCol = 0;
-      }
-      //print(inSplice+" / "+isCurLineInSplice()+" / "+curSplice[0]+" / "+curSplice[1]+" / "+lines.length);
-/*if (inSplice && (! isCurLineInSplice()) && (curSplice[0] + curSplice[1] < lines.length)) {
-	  print("BLAH");
-	  putCurLineInSplice();
-	}*/
-      // tests case foo in remove(), which isn't otherwise covered in current impl
-    }
-    //debugPrint("skip");
-  }
-
-  function skip(N, L, includeInSplice)
-  {
-    if (N)
-    {
-      if (L)
-      {
-        skipLines(L, includeInSplice);
-      }
-      else
-      {
-        if (includeInSplice && !inSplice)
-        {
-          enterSplice();
-        }
-        if (inSplice)
-        {
-          putCurLineInSplice();
-        }
-        curCol += N;
-        //debugPrint("skip");
-      }
-    }
-  }
-
-  function removeLines(L)
-  {
-    var removed = '';
-    if (L)
-    {
-      if (!inSplice)
-      {
-        enterSplice();
-      }
-
-      function nextKLinesText(k)
-      {
-        var m = curSplice[0] + curSplice[1];
-        return lines_slice(m, m + k).join('');
-      }
-      if (isCurLineInSplice())
-      {
-        //print(curCol);
-        if (curCol == 0)
-        {
-          removed = curSplice[curSplice.length - 1];
-          // print("FOO"); // case foo
-          curSplice.length--;
-          removed += nextKLinesText(L - 1);
-          curSplice[1] += L - 1;
-        }
-        else
-        {
-          removed = nextKLinesText(L - 1);
-          curSplice[1] += L - 1;
-          var sline = curSplice.length - 1;
-          removed = curSplice[sline].substring(curCol) + removed;
-          curSplice[sline] = curSplice[sline].substring(0, curCol) + lines_get(curSplice[0] + curSplice[1]);
-          curSplice[1] += 1;
-        }
-      }
-      else
-      {
-        removed = nextKLinesText(L);
-        curSplice[1] += L;
-      }
-      //debugPrint("remove");
-    }
-    return removed;
-  }
-
-  function remove(N, L)
-  {
-    var removed = '';
-    if (N)
-    {
-      if (L)
-      {
-        return removeLines(L);
-      }
-      else
-      {
-        if (!inSplice)
-        {
-          enterSplice();
-        }
-        var sline = putCurLineInSplice();
-        removed = curSplice[sline].substring(curCol, curCol + N);
-        curSplice[sline] = curSplice[sline].substring(0, curCol) + curSplice[sline].substring(curCol + N);
-        //debugPrint("remove");
-      }
-    }
-    return removed;
-  }
-
-  function insert(text, L)
-  {
-    if (text)
-    {
-      if (!inSplice)
-      {
-        enterSplice();
-      }
-      if (L)
-      {
-        var newLines = Changeset.splitTextLines(text);
-        if (isCurLineInSplice())
-        {
-          //if (curCol == 0) {
-          //curSplice.length--;
-          //curSplice[1]--;
-          //Array.prototype.push.apply(curSplice, newLines);
-          //curLine += newLines.length;
-          //}
-          //else {
-          var sline = curSplice.length - 1;
-          var theLine = curSplice[sline];
-          var lineCol = curCol;
-          curSplice[sline] = theLine.substring(0, lineCol) + newLines[0];
-          curLine++;
-          newLines.splice(0, 1);
-          Array.prototype.push.apply(curSplice, newLines);
-          curLine += newLines.length;
-          curSplice.push(theLine.substring(lineCol));
-          curCol = 0;
-          //}
-        }
-        else
-        {
-          Array.prototype.push.apply(curSplice, newLines);
-          curLine += newLines.length;
-        }
-      }
-      else
-      {
-        var sline = putCurLineInSplice();
-        curSplice[sline] = curSplice[sline].substring(0, curCol) + text + curSplice[sline].substring(curCol);
-        curCol += text.length;
-      }
-      //debugPrint("insert");
-    }
-  }
-
-  function hasMore()
-  {
-    //print(lines.length+" / "+inSplice+" / "+(curSplice.length - 2)+" / "+curSplice[1]);
-    var docLines = lines_length();
-    if (inSplice)
-    {
-      docLines += curSplice.length - 2 - curSplice[1];
-    }
-    return curLine < docLines;
-  }
-
-  function close()
-  {
-    if (inSplice)
-    {
-      leaveSplice();
-    }
-    //debugPrint("close");
-  }
-
-  var self = {
-    skip: skip,
-    remove: remove,
-    insert: insert,
-    close: close,
-    hasMore: hasMore,
-    removeLines: removeLines,
-    skipLines: skipLines
-  };
-  return self;
-};
-
-Changeset.applyZip = function(in1, idx1, in2, idx2, func)
-{
-  var iter1 = Changeset.opIterator(in1, idx1);
-  var iter2 = Changeset.opIterator(in2, idx2);
-  var assem = Changeset.smartOpAssembler();
-  var op1 = Changeset.newOp();
-  var op2 = Changeset.newOp();
-  var opOut = Changeset.newOp();
-  while (op1.opcode || iter1.hasNext() || op2.opcode || iter2.hasNext())
-  {
-    if ((!op1.opcode) && iter1.hasNext()) iter1.next(op1);
-    if ((!op2.opcode) && iter2.hasNext()) iter2.next(op2);
-    func(op1, op2, opOut);
-    if (opOut.opcode)
-    {
-      //print(opOut.toSource());
-      assem.append(opOut);
-      opOut.opcode = '';
-    }
-  }
-  assem.endDocument();
-  return assem.toString();
-};
-
-Changeset.unpack = function(cs)
-{
-  var headerRegex = /Z:([0-9a-z]+)([><])([0-9a-z]+)|/;
-  var headerMatch = headerRegex.exec(cs);
-  if ((!headerMatch) || (!headerMatch[0]))
-  {
-    Changeset.error("Not a changeset: " + cs);
-  }
-  var oldLen = Changeset.parseNum(headerMatch[1]);
-  var changeSign = (headerMatch[2] == '>') ? 1 : -1;
-  var changeMag = Changeset.parseNum(headerMatch[3]);
-  var newLen = oldLen + changeSign * changeMag;
-  var opsStart = headerMatch[0].length;
-  var opsEnd = cs.indexOf("$");
-  if (opsEnd < 0) opsEnd = cs.length;
-  return {
-    oldLen: oldLen,
-    newLen: newLen,
-    ops: cs.substring(opsStart, opsEnd),
-    charBank: cs.substring(opsEnd + 1)
-  };
-};
-
-Changeset.pack = function(oldLen, newLen, opsStr, bank)
-{
-  var lenDiff = newLen - oldLen;
-  var lenDiffStr = (lenDiff >= 0 ? '>' + Changeset.numToString(lenDiff) : '<' + Changeset.numToString(-lenDiff));
-  var a = [];
-  a.push('Z:', Changeset.numToString(oldLen), lenDiffStr, opsStr, '$', bank);
-  return a.join('');
-};
-
-Changeset.applyToText = function(cs, str)
-{
-  var unpacked = Changeset.unpack(cs);
-  Changeset.assert(str.length == unpacked.oldLen, "mismatched apply: ", str.length, " / ", unpacked.oldLen);
-  var csIter = Changeset.opIterator(unpacked.ops);
-  var bankIter = Changeset.stringIterator(unpacked.charBank);
-  var strIter = Changeset.stringIterator(str);
-  var assem = Changeset.stringAssembler();
-  while (csIter.hasNext())
-  {
-    var op = csIter.next();
-    switch (op.opcode)
-    {
-    case '+':
-      assem.append(bankIter.take(op.chars));
-      break;
-    case '-':
-      strIter.skip(op.chars);
-      break;
-    case '=':
-      assem.append(strIter.take(op.chars));
-      break;
-    }
-  }
-  assem.append(strIter.take(strIter.remaining()));
-  return assem.toString();
-};
-
-Changeset.mutateTextLines = function(cs, lines)
-{
-  var unpacked = Changeset.unpack(cs);
-  var csIter = Changeset.opIterator(unpacked.ops);
-  var bankIter = Changeset.stringIterator(unpacked.charBank);
-  var mut = Changeset.textLinesMutator(lines);
-  while (csIter.hasNext())
-  {
-    var op = csIter.next();
-    switch (op.opcode)
-    {
-    case '+':
-      mut.insert(bankIter.take(op.chars), op.lines);
-      break;
-    case '-':
-      mut.remove(op.chars, op.lines);
-      break;
-    case '=':
-      mut.skip(op.chars, op.lines, ( !! op.attribs));
-      break;
-    }
-  }
-  mut.close();
-};
-
-Changeset.composeAttributes = function(att1, att2, resultIsMutation, pool)
-{
-  // att1 and att2 are strings like "*3*f*1c", asMutation is a boolean.
-  // Sometimes attribute (key,value) pairs are treated as attribute presence
-  // information, while other times they are treated as operations that
-  // mutate a set of attributes, and this affects whether an empty value
-  // is a deletion or a change.
-  // Examples, of the form (att1Items, att2Items, resultIsMutation) -> result
-  // ([], [(bold, )], true) -> [(bold, )]
-  // ([], [(bold, )], false) -> []
-  // ([], [(bold, true)], true) -> [(bold, true)]
-  // ([], [(bold, true)], false) -> [(bold, true)]
-  // ([(bold, true)], [(bold, )], true) -> [(bold, )]
-  // ([(bold, true)], [(bold, )], false) -> []
-  // pool can be null if att2 has no attributes.
-  if ((!att1) && resultIsMutation)
-  {
-    // In the case of a mutation (i.e. composing two changesets),
-    // an att2 composed with an empy att1 is just att2.  If att1
-    // is part of an attribution string, then att2 may remove
-    // attributes that are already gone, so don't do this optimization.
-    return att2;
-  }
-  if (!att2) return att1;
-  var atts = [];
-  att1.replace(/\*([0-9a-z]+)/g, function(_, a)
-  {
-    atts.push(pool.getAttrib(Changeset.parseNum(a)));
-    return '';
-  });
-  att2.replace(/\*([0-9a-z]+)/g, function(_, a)
-  {
-    var pair = pool.getAttrib(Changeset.parseNum(a));
-    var found = false;
-    for (var i = 0; i < atts.length; i++)
-    {
-      var oldPair = atts[i];
-      if (oldPair[0] == pair[0])
-      {
-        if (pair[1] || resultIsMutation)
-        {
-          oldPair[1] = pair[1];
-        }
-        else
-        {
-          atts.splice(i, 1);
-        }
-        found = true;
-        break;
-      }
-    }
-    if ((!found) && (pair[1] || resultIsMutation))
-    {
-      atts.push(pair);
-    }
-    return '';
-  });
-  atts.sort();
-  var buf = Changeset.stringAssembler();
-  for (var i = 0; i < atts.length; i++)
-  {
-    buf.append('*');
-    buf.append(Changeset.numToString(pool.putAttrib(atts[i])));
-  }
-  //print(att1+" / "+att2+" / "+buf.toString());
-  return buf.toString();
-};
-
-Changeset._slicerZipperFunc = function(attOp, csOp, opOut, pool)
-{
-  // attOp is the op from the sequence that is being operated on, either an
-  // attribution string or the earlier of two changesets being composed.
-  // pool can be null if definitely not needed.
-  //print(csOp.toSource()+" "+attOp.toSource()+" "+opOut.toSource());
-  if (attOp.opcode == '-')
-  {
-    Changeset.copyOp(attOp, opOut);
-    attOp.opcode = '';
-  }
-  else if (!attOp.opcode)
-  {
-    Changeset.copyOp(csOp, opOut);
-    csOp.opcode = '';
-  }
-  else
-  {
-    switch (csOp.opcode)
-    {
-    case '-':
-      {
-        if (csOp.chars <= attOp.chars)
-        {
-          // delete or delete part
-          if (attOp.opcode == '=')
-          {
-            opOut.opcode = '-';
-            opOut.chars = csOp.chars;
-            opOut.lines = csOp.lines;
-            opOut.attribs = '';
-          }
-          attOp.chars -= csOp.chars;
-          attOp.lines -= csOp.lines;
-          csOp.opcode = '';
-          if (!attOp.chars)
-          {
-            attOp.opcode = '';
-          }
-        }
-        else
-        {
-          // delete and keep going
-          if (attOp.opcode == '=')
-          {
-            opOut.opcode = '-';
-            opOut.chars = attOp.chars;
-            opOut.lines = attOp.lines;
-            opOut.attribs = '';
-          }
-          csOp.chars -= attOp.chars;
-          csOp.lines -= attOp.lines;
-          attOp.opcode = '';
-        }
-        break;
-      }
-    case '+':
-      {
-        // insert
-        Changeset.copyOp(csOp, opOut);
-        csOp.opcode = '';
-        break;
-      }
-    case '=':
-      {
-        if (csOp.chars <= attOp.chars)
-        {
-          // keep or keep part
-          opOut.opcode = attOp.opcode;
-          opOut.chars = csOp.chars;
-          opOut.lines = csOp.lines;
-          opOut.attribs = Changeset.composeAttributes(attOp.attribs, csOp.attribs, attOp.opcode == '=', pool);
-          csOp.opcode = '';
-          attOp.chars -= csOp.chars;
-          attOp.lines -= csOp.lines;
-          if (!attOp.chars)
-          {
-            attOp.opcode = '';
-          }
-        }
-        else
-        {
-          // keep and keep going
-          opOut.opcode = attOp.opcode;
-          opOut.chars = attOp.chars;
-          opOut.lines = attOp.lines;
-          opOut.attribs = Changeset.composeAttributes(attOp.attribs, csOp.attribs, attOp.opcode == '=', pool);
-          attOp.opcode = '';
-          csOp.chars -= attOp.chars;
-          csOp.lines -= attOp.lines;
-        }
-        break;
-      }
-    case '':
-      {
-        Changeset.copyOp(attOp, opOut);
-        attOp.opcode = '';
-        break;
-      }
-    }
-  }
-};
-
-Changeset.applyToAttribution = function(cs, astr, pool)
-{
-  var unpacked = Changeset.unpack(cs);
-
-  return Changeset.applyZip(astr, 0, unpacked.ops, 0, function(op1, op2, opOut)
-  {
-    return Changeset._slicerZipperFunc(op1, op2, opOut, pool);
-  });
-};
-
-/*Changeset.oneInsertedLineAtATimeOpIterator = function(opsStr, optStartIndex, charBank) {
-  var iter = Changeset.opIterator(opsStr, optStartIndex);
-  var bankIndex = 0;
-
-};*/
-
-Changeset.mutateAttributionLines = function(cs, lines, pool)
-{
-  //dmesg(cs);
-  //dmesg(lines.toSource()+" ->");
-  var unpacked = Changeset.unpack(cs);
-  var csIter = Changeset.opIterator(unpacked.ops);
-  var csBank = unpacked.charBank;
-  var csBankIndex = 0;
-  // treat the attribution lines as text lines, mutating a line at a time
-  var mut = Changeset.textLinesMutator(lines);
-
-  var lineIter = null;
-
-  function isNextMutOp()
-  {
-    return (lineIter && lineIter.hasNext()) || mut.hasMore();
-  }
-
-  function nextMutOp(destOp)
-  {
-    if ((!(lineIter && lineIter.hasNext())) && mut.hasMore())
-    {
-      var line = mut.removeLines(1);
-      lineIter = Changeset.opIterator(line);
-    }
-    if (lineIter && lineIter.hasNext())
-    {
-      lineIter.next(destOp);
-    }
-    else
-    {
-      destOp.opcode = '';
-    }
-  }
-  var lineAssem = null;
-
-  function outputMutOp(op)
-  {
-    //print("outputMutOp: "+op.toSource());
-    if (!lineAssem)
-    {
-      lineAssem = Changeset.mergingOpAssembler();
-    }
-    lineAssem.append(op);
-    if (op.lines > 0)
-    {
-      Changeset.assert(op.lines == 1, "Can't have op.lines of ", op.lines, " in attribution lines");
-      // ship it to the mut
-      mut.insert(lineAssem.toString(), 1);
-      lineAssem = null;
-    }
-  }
-
-  var csOp = Changeset.newOp();
-  var attOp = Changeset.newOp();
-  var opOut = Changeset.newOp();
-  while (csOp.opcode || csIter.hasNext() || attOp.opcode || isNextMutOp())
-  {
-    if ((!csOp.opcode) && csIter.hasNext())
-    {
-      csIter.next(csOp);
-    }
-    //print(csOp.toSource()+" "+attOp.toSource()+" "+opOut.toSource());
-    //print(csOp.opcode+"/"+csOp.lines+"/"+csOp.attribs+"/"+lineAssem+"/"+lineIter+"/"+(lineIter?lineIter.hasNext():null));
-    //print("csOp: "+csOp.toSource());
-    if ((!csOp.opcode) && (!attOp.opcode) && (!lineAssem) && (!(lineIter && lineIter.hasNext())))
-    {
-      break; // done
-    }
-    else if (csOp.opcode == '=' && csOp.lines > 0 && (!csOp.attribs) && (!attOp.opcode) && (!lineAssem) && (!(lineIter && lineIter.hasNext())))
-    {
-      // skip multiple lines; this is what makes small changes not order of the document size
-      mut.skipLines(csOp.lines);
-      //print("skipped: "+csOp.lines);
-      csOp.opcode = '';
-    }
-    else if (csOp.opcode == '+')
-    {
-      if (csOp.lines > 1)
-      {
-        var firstLineLen = csBank.indexOf('\n', csBankIndex) + 1 - csBankIndex;
-        Changeset.copyOp(csOp, opOut);
-        csOp.chars -= firstLineLen;
-        csOp.lines--;
-        opOut.lines = 1;
-        opOut.chars = firstLineLen;
-      }
-      else
-      {
-        Changeset.copyOp(csOp, opOut);
-        csOp.opcode = '';
-      }
-      outputMutOp(opOut);
-      csBankIndex += opOut.chars;
-      opOut.opcode = '';
-    }
-    else
-    {
-      if ((!attOp.opcode) && isNextMutOp())
-      {
-        nextMutOp(attOp);
-      }
-      //print("attOp: "+attOp.toSource());
-      Changeset._slicerZipperFunc(attOp, csOp, opOut, pool);
-      if (opOut.opcode)
-      {
-        outputMutOp(opOut);
-        opOut.opcode = '';
-      }
-    }
-  }
-
-  Changeset.assert(!lineAssem, "line assembler not finished");
-  mut.close();
-
-  //dmesg("-> "+lines.toSource());
-};
-
-Changeset.joinAttributionLines = function(theAlines)
-{
-  var assem = Changeset.mergingOpAssembler();
-  for (var i = 0; i < theAlines.length; i++)
-  {
-    var aline = theAlines[i];
-    var iter = Changeset.opIterator(aline);
-    while (iter.hasNext())
-    {
-      assem.append(iter.next());
-    }
-  }
-  return assem.toString();
-};
-
-Changeset.splitAttributionLines = function(attrOps, text)
-{
-  var iter = Changeset.opIterator(attrOps);
-  var assem = Changeset.mergingOpAssembler();
-  var lines = [];
-  var pos = 0;
-
-  function appendOp(op)
-  {
-    assem.append(op);
-    if (op.lines > 0)
-    {
-      lines.push(assem.toString());
-      assem.clear();
-    }
-    pos += op.chars;
-  }
-
-  while (iter.hasNext())
-  {
-    var op = iter.next();
-    var numChars = op.chars;
-    var numLines = op.lines;
-    while (numLines > 1)
-    {
-      var newlineEnd = text.indexOf('\n', pos) + 1;
-      Changeset.assert(newlineEnd > 0, "newlineEnd <= 0 in splitAttributionLines");
-      op.chars = newlineEnd - pos;
-      op.lines = 1;
-      appendOp(op);
-      numChars -= op.chars;
-      numLines -= op.lines;
-    }
-    if (numLines == 1)
-    {
-      op.chars = numChars;
-      op.lines = 1;
-    }
-    appendOp(op);
-  }
-
-  return lines;
-};
-
-Changeset.splitTextLines = function(text)
-{
-  return text.match(/[^\n]*(?:\n|[^\n]$)/g);
-};
-
-Changeset.compose = function(cs1, cs2, pool)
-{
-  var unpacked1 = Changeset.unpack(cs1);
-  var unpacked2 = Changeset.unpack(cs2);
-  var len1 = unpacked1.oldLen;
-  var len2 = unpacked1.newLen;
-  Changeset.assert(len2 == unpacked2.oldLen, "mismatched composition");
-  var len3 = unpacked2.newLen;
-  var bankIter1 = Changeset.stringIterator(unpacked1.charBank);
-  var bankIter2 = Changeset.stringIterator(unpacked2.charBank);
-  var bankAssem = Changeset.stringAssembler();
-
-  var newOps = Changeset.applyZip(unpacked1.ops, 0, unpacked2.ops, 0, function(op1, op2, opOut)
-  {
-    //var debugBuilder = Changeset.stringAssembler();
-    //debugBuilder.append(Changeset.opString(op1));
-    //debugBuilder.append(',');
-    //debugBuilder.append(Changeset.opString(op2));
-    //debugBuilder.append(' / ');
-    var op1code = op1.opcode;
-    var op2code = op2.opcode;
-    if (op1code == '+' && op2code == '-')
-    {
-      bankIter1.skip(Math.min(op1.chars, op2.chars));
-    }
-    Changeset._slicerZipperFunc(op1, op2, opOut, pool);
-    if (opOut.opcode == '+')
-    {
-      if (op2code == '+')
-      {
-        bankAssem.append(bankIter2.take(opOut.chars));
-      }
-      else
-      {
-        bankAssem.append(bankIter1.take(opOut.chars));
-      }
-    }
-
-    //debugBuilder.append(Changeset.opString(op1));
-    //debugBuilder.append(',');
-    //debugBuilder.append(Changeset.opString(op2));
-    //debugBuilder.append(' -> ');
-    //debugBuilder.append(Changeset.opString(opOut));
-    //print(debugBuilder.toString());
-  });
-
-  return Changeset.pack(len1, len3, newOps, bankAssem.toString());
-};
-
-Changeset.attributeTester = function(attribPair, pool)
-{
-  // returns a function that tests if a string of attributes
-  // (e.g. *3*4) contains a given attribute key,value that
-  // is already present in the pool.
-  if (!pool)
-  {
-    return never;
-  }
-  var attribNum = pool.putAttrib(attribPair, true);
-  if (attribNum < 0)
-  {
-    return never;
-  }
-  else
-  {
-    var re = new RegExp('\\*' + Changeset.numToString(attribNum) + '(?!\\w)');
-    return function(attribs)
-    {
-      return re.test(attribs);
-    };
-  }
-
-  function never(attribs)
-  {
-    return false;
-  }
-};
-
-Changeset.identity = function(N)
-{
-  return Changeset.pack(N, N, "", "");
-};
-
-Changeset.makeSplice = function(oldFullText, spliceStart, numRemoved, newText, optNewTextAPairs, pool)
-{
-  var oldLen = oldFullText.length;
-
-  if (spliceStart >= oldLen)
-  {
-    spliceStart = oldLen - 1;
-  }
-  if (numRemoved > oldFullText.length - spliceStart - 1)
-  {
-    numRemoved = oldFullText.length - spliceStart - 1;
-  }
-  var oldText = oldFullText.substring(spliceStart, spliceStart + numRemoved);
-  var newLen = oldLen + newText.length - oldText.length;
-
-  var assem = Changeset.smartOpAssembler();
-  assem.appendOpWithText('=', oldFullText.substring(0, spliceStart));
-  assem.appendOpWithText('-', oldText);
-  assem.appendOpWithText('+', newText, optNewTextAPairs, pool);
-  assem.endDocument();
-  return Changeset.pack(oldLen, newLen, assem.toString(), newText);
-};
-
-Changeset.toSplices = function(cs)
-{
-  // get a list of splices, [startChar, endChar, newText]
-  var unpacked = Changeset.unpack(cs);
-  var splices = [];
-
-  var oldPos = 0;
-  var iter = Changeset.opIterator(unpacked.ops);
-  var charIter = Changeset.stringIterator(unpacked.charBank);
-  var inSplice = false;
-  while (iter.hasNext())
-  {
-    var op = iter.next();
-    if (op.opcode == '=')
-    {
-      oldPos += op.chars;
-      inSplice = false;
-    }
-    else
-    {
-      if (!inSplice)
-      {
-        splices.push([oldPos, oldPos, ""]);
-        inSplice = true;
-      }
-      if (op.opcode == '-')
-      {
-        oldPos += op.chars;
-        splices[splices.length - 1][1] += op.chars;
-      }
-      else if (op.opcode == '+')
-      {
-        splices[splices.length - 1][2] += charIter.take(op.chars);
-      }
-    }
-  }
-
-  return splices;
-};
-
-Changeset.characterRangeFollow = function(cs, startChar, endChar, insertionsAfter)
-{
-  var newStartChar = startChar;
-  var newEndChar = endChar;
-  var splices = Changeset.toSplices(cs);
-  var lengthChangeSoFar = 0;
-  for (var i = 0; i < splices.length; i++)
-  {
-    var splice = splices[i];
-    var spliceStart = splice[0] + lengthChangeSoFar;
-    var spliceEnd = splice[1] + lengthChangeSoFar;
-    var newTextLength = splice[2].length;
-    var thisLengthChange = newTextLength - (spliceEnd - spliceStart);
-
-    if (spliceStart <= newStartChar && spliceEnd >= newEndChar)
-    {
-      // splice fully replaces/deletes range
-      // (also case that handles insertion at a collapsed selection)
-      if (insertionsAfter)
-      {
-        newStartChar = newEndChar = spliceStart;
-      }
-      else
-      {
-        newStartChar = newEndChar = spliceStart + newTextLength;
-      }
-    }
-    else if (spliceEnd <= newStartChar)
-    {
-      // splice is before range
-      newStartChar += thisLengthChange;
-      newEndChar += thisLengthChange;
-    }
-    else if (spliceStart >= newEndChar)
-    {
-      // splice is after range
-    }
-    else if (spliceStart >= newStartChar && spliceEnd <= newEndChar)
-    {
-      // splice is inside range
-      newEndChar += thisLengthChange;
-    }
-    else if (spliceEnd < newEndChar)
-    {
-      // splice overlaps beginning of range
-      newStartChar = spliceStart + newTextLength;
-      newEndChar += thisLengthChange;
-    }
-    else
-    {
-      // splice overlaps end of range
-      newEndChar = spliceStart;
-    }
-
-    lengthChangeSoFar += thisLengthChange;
-  }
-
-  return [newStartChar, newEndChar];
-};
-
-Changeset.moveOpsToNewPool = function(cs, oldPool, newPool)
-{
-  // works on changeset or attribution string
-  var dollarPos = cs.indexOf('$');
-  if (dollarPos < 0)
-  {
-    dollarPos = cs.length;
-  }
-  var upToDollar = cs.substring(0, dollarPos);
-  var fromDollar = cs.substring(dollarPos);
-  // order of attribs stays the same
-  return upToDollar.replace(/\*([0-9a-z]+)/g, function(_, a)
-  {
-    var oldNum = Changeset.parseNum(a);
-    var pair = oldPool.getAttrib(oldNum);
-    var newNum = newPool.putAttrib(pair);
-    return '*' + Changeset.numToString(newNum);
-  }) + fromDollar;
-};
-
-Changeset.makeAttribution = function(text)
-{
-  var assem = Changeset.smartOpAssembler();
-  assem.appendOpWithText('+', text);
-  return assem.toString();
-};
-
-// callable on a changeset, attribution string, or attribs property of an op
-Changeset.eachAttribNumber = function(cs, func)
-{
-  var dollarPos = cs.indexOf('$');
-  if (dollarPos < 0)
-  {
-    dollarPos = cs.length;
-  }
-  var upToDollar = cs.substring(0, dollarPos);
-
-  upToDollar.replace(/\*([0-9a-z]+)/g, function(_, a)
-  {
-    func(Changeset.parseNum(a));
-    return '';
-  });
-};
-
-// callable on a changeset, attribution string, or attribs property of an op,
-// though it may easily create adjacent ops that can be merged.
-Changeset.filterAttribNumbers = function(cs, filter)
-{
-  return Changeset.mapAttribNumbers(cs, filter);
-};
-
-Changeset.mapAttribNumbers = function(cs, func)
-{
-  var dollarPos = cs.indexOf('$');
-  if (dollarPos < 0)
-  {
-    dollarPos = cs.length;
-  }
-  var upToDollar = cs.substring(0, dollarPos);
-
-  var newUpToDollar = upToDollar.replace(/\*([0-9a-z]+)/g, function(s, a)
-  {
-    var n = func(Changeset.parseNum(a));
-    if (n === true)
-    {
-      return s;
-    }
-    else if ((typeof n) === "number")
-    {
-      return '*' + Changeset.numToString(n);
-    }
-    else
-    {
-      return '';
-    }
-  });
-
-  return newUpToDollar + cs.substring(dollarPos);
-};
-
-Changeset.makeAText = function(text, attribs)
-{
-  return {
-    text: text,
-    attribs: (attribs || Changeset.makeAttribution(text))
-  };
-};
-
-Changeset.applyToAText = function(cs, atext, pool)
-{
-  return {
-    text: Changeset.applyToText(cs, atext.text),
-    attribs: Changeset.applyToAttribution(cs, atext.attribs, pool)
-  };
-};
-
-Changeset.cloneAText = function(atext)
-{
-  return {
-    text: atext.text,
-    attribs: atext.attribs
-  };
-};
-
-Changeset.copyAText = function(atext1, atext2)
-{
-  atext2.text = atext1.text;
-  atext2.attribs = atext1.attribs;
-};
-
-Changeset.appendATextToAssembler = function(atext, assem)
-{
-  // intentionally skips last newline char of atext
-  var iter = Changeset.opIterator(atext.attribs);
-  var op = Changeset.newOp();
-  while (iter.hasNext())
-  {
-    iter.next(op);
-    if (!iter.hasNext())
-    {
-      // last op, exclude final newline
-      if (op.lines <= 1)
-      {
-        op.lines = 0;
-        op.chars--;
-        if (op.chars)
-        {
-          assem.append(op);
-        }
-      }
-      else
-      {
-        var nextToLastNewlineEnd = atext.text.lastIndexOf('\n', atext.text.length - 2) + 1;
-        var lastLineLength = atext.text.length - nextToLastNewlineEnd - 1;
-        op.lines--;
-        op.chars -= (lastLineLength + 1);
-        assem.append(op);
-        op.lines = 0;
-        op.chars = lastLineLength;
-        if (op.chars)
-        {
-          assem.append(op);
-        }
-      }
-    }
-    else
-    {
-      assem.append(op);
-    }
-  }
-};
-
-Changeset.prepareForWire = function(cs, pool)
-{
-  var newPool = new AttribPool();
-  var newCs = Changeset.moveOpsToNewPool(cs, pool, newPool);
-  return {
-    translated: newCs,
-    pool: newPool
-  };
-};
-
-Changeset.isIdentity = function(cs)
-{
-  var unpacked = Changeset.unpack(cs);
-  return unpacked.ops == "" && unpacked.oldLen == unpacked.newLen;
-};
-
-Changeset.opAttributeValue = function(op, key, pool)
-{
-  return Changeset.attribsAttributeValue(op.attribs, key, pool);
-};
-
-Changeset.attribsAttributeValue = function(attribs, key, pool)
-{
-  var value = '';
-  if (attribs)
-  {
-    Changeset.eachAttribNumber(attribs, function(n)
-    {
-      if (pool.getAttribKey(n) == key)
-      {
-        value = pool.getAttribValue(n);
-      }
-    });
-  }
-  return value;
-};
-
-Changeset.builder = function(oldLen)
-{
-  var assem = Changeset.smartOpAssembler();
-  var o = Changeset.newOp();
-  var charBank = Changeset.stringAssembler();
-
-  var self = {
-    // attribs are [[key1,value1],[key2,value2],...] or '*0*1...' (no pool needed in latter case)
-    keep: function(N, L, attribs, pool)
-    {
-      o.opcode = '=';
-      o.attribs = (attribs && Changeset.makeAttribsString('=', attribs, pool)) || '';
-      o.chars = N;
-      o.lines = (L || 0);
-      assem.append(o);
-      return self;
-    },
-    keepText: function(text, attribs, pool)
-    {
-      assem.appendOpWithText('=', text, attribs, pool);
-      return self;
-    },
-    insert: function(text, attribs, pool)
-    {
-      assem.appendOpWithText('+', text, attribs, pool);
-      charBank.append(text);
-      return self;
-    },
-    remove: function(N, L)
-    {
-      o.opcode = '-';
-      o.attribs = '';
-      o.chars = N;
-      o.lines = (L || 0);
-      assem.append(o);
-      return self;
-    },
-    toString: function()
-    {
-      assem.endDocument();
-      var newLen = oldLen + assem.getLengthChange();
-      return Changeset.pack(oldLen, newLen, assem.toString(), charBank.toString());
-    }
-  };
-
-  return self;
-};
-
-Changeset.makeAttribsString = function(opcode, attribs, pool)
-{
-  // makeAttribsString(opcode, '*3') or makeAttribsString(opcode, [['foo','bar']], myPool) work
-  if (!attribs)
-  {
-    return '';
-  }
-  else if ((typeof attribs) == "string")
-  {
-    return attribs;
-  }
-  else if (pool && attribs && attribs.length)
-  {
-    if (attribs.length > 1)
-    {
-      attribs = attribs.slice();
-      attribs.sort();
-    }
-    var result = [];
-    for (var i = 0; i < attribs.length; i++)
-    {
-      var pair = attribs[i];
-      if (opcode == '=' || (opcode == '+' && pair[1]))
-      {
-        result.push('*' + Changeset.numToString(pool.putAttrib(pair)));
-      }
-    }
-    return result.join('');
-  }
-};
-
-// like "substring" but on a single-line attribution string
-Changeset.subattribution = function(astr, start, optEnd)
-{
-  var iter = Changeset.opIterator(astr, 0);
-  var assem = Changeset.smartOpAssembler();
-  var attOp = Changeset.newOp();
-  var csOp = Changeset.newOp();
-  var opOut = Changeset.newOp();
-
-  function doCsOp()
-  {
-    if (csOp.chars)
-    {
-      while (csOp.opcode && (attOp.opcode || iter.hasNext()))
-      {
-        if (!attOp.opcode) iter.next(attOp);
-
-        if (csOp.opcode && attOp.opcode && csOp.chars >= attOp.chars && attOp.lines > 0 && csOp.lines <= 0)
-        {
-          csOp.lines++;
-        }
-
-        Changeset._slicerZipperFunc(attOp, csOp, opOut, null);
-        if (opOut.opcode)
-        {
-          assem.append(opOut);
-          opOut.opcode = '';
-        }
-      }
-    }
-  }
-
-  csOp.opcode = '-';
-  csOp.chars = start;
-
-  doCsOp();
-
-  if (optEnd === undefined)
-  {
-    if (attOp.opcode)
-    {
-      assem.append(attOp);
-    }
-    while (iter.hasNext())
-    {
-      iter.next(attOp);
-      assem.append(attOp);
-    }
-  }
-  else
-  {
-    csOp.opcode = '=';
-    csOp.chars = optEnd - start;
-    doCsOp();
-  }
-
-  return assem.toString();
-};
-
-Changeset.inverse = function(cs, lines, alines, pool)
-{
-  // lines and alines are what the changeset is meant to apply to.
-  // They may be arrays or objects with .get(i) and .length methods.
-  // They include final newlines on lines.
-
-  function lines_get(idx)
-  {
-    if (lines.get)
-    {
-      return lines.get(idx);
-    }
-    else
-    {
-      return lines[idx];
-    }
-  }
-
-  function lines_length()
-  {
-    if ((typeof lines.length) == "number")
-    {
-      return lines.length;
-    }
-    else
-    {
-      return lines.length();
-    }
-  }
-
-  function alines_get(idx)
-  {
-    if (alines.get)
-    {
-      return alines.get(idx);
-    }
-    else
-    {
-      return alines[idx];
-    }
-  }
-
-  function alines_length()
-  {
-    if ((typeof alines.length) == "number")
-    {
-      return alines.length;
-    }
-    else
-    {
-      return alines.length();
-    }
-  }
-
-  var curLine = 0;
-  var curChar = 0;
-  var curLineOpIter = null;
-  var curLineOpIterLine;
-  var curLineNextOp = Changeset.newOp('+');
-
-  var unpacked = Changeset.unpack(cs);
-  var csIter = Changeset.opIterator(unpacked.ops);
-  var builder = Changeset.builder(unpacked.newLen);
-
-  function consumeAttribRuns(numChars, func /*(len, attribs, endsLine)*/ )
-  {
-
-    if ((!curLineOpIter) || (curLineOpIterLine != curLine))
-    {
-      // create curLineOpIter and advance it to curChar
-      curLineOpIter = Changeset.opIterator(alines_get(curLine));
-      curLineOpIterLine = curLine;
-      var indexIntoLine = 0;
-      var done = false;
-      while (!done)
-      {
-        curLineOpIter.next(curLineNextOp);
-        if (indexIntoLine + curLineNextOp.chars >= curChar)
-        {
-          curLineNextOp.chars -= (curChar - indexIntoLine);
-          done = true;
-        }
-        else
-        {
-          indexIntoLine += curLineNextOp.chars;
-        }
-      }
-    }
-
-    while (numChars > 0)
-    {
-      if ((!curLineNextOp.chars) && (!curLineOpIter.hasNext()))
-      {
-        curLine++;
-        curChar = 0;
-        curLineOpIterLine = curLine;
-        curLineNextOp.chars = 0;
-        curLineOpIter = Changeset.opIterator(alines_get(curLine));
-      }
-      if (!curLineNextOp.chars)
-      {
-        curLineOpIter.next(curLineNextOp);
-      }
-      var charsToUse = Math.min(numChars, curLineNextOp.chars);
-      func(charsToUse, curLineNextOp.attribs, charsToUse == curLineNextOp.chars && curLineNextOp.lines > 0);
-      numChars -= charsToUse;
-      curLineNextOp.chars -= charsToUse;
-      curChar += charsToUse;
-    }
-
-    if ((!curLineNextOp.chars) && (!curLineOpIter.hasNext()))
-    {
-      curLine++;
-      curChar = 0;
-    }
-  }
-
-  function skip(N, L)
-  {
-    if (L)
-    {
-      curLine += L;
-      curChar = 0;
-    }
-    else
-    {
-      if (curLineOpIter && curLineOpIterLine == curLine)
-      {
-        consumeAttribRuns(N, function()
-        {});
-      }
-      else
-      {
-        curChar += N;
-      }
-    }
-  }
-
-  function nextText(numChars)
-  {
-    var len = 0;
-    var assem = Changeset.stringAssembler();
-    var firstString = lines_get(curLine).substring(curChar);
-    len += firstString.length;
-    assem.append(firstString);
-
-    var lineNum = curLine + 1;
-    while (len < numChars)
-    {
-      var nextString = lines_get(lineNum);
-      len += nextString.length;
-      assem.append(nextString);
-      lineNum++;
-    }
-
-    return assem.toString().substring(0, numChars);
-  }
-
-  function cachedStrFunc(func)
-  {
-    var cache = {};
-    return function(s)
-    {
-      if (!cache[s])
-      {
-        cache[s] = func(s);
-      }
-      return cache[s];
-    };
-  }
-
-  var attribKeys = [];
-  var attribValues = [];
-  while (csIter.hasNext())
-  {
-    var csOp = csIter.next();
-    if (csOp.opcode == '=')
-    {
-      if (csOp.attribs)
-      {
-        attribKeys.length = 0;
-        attribValues.length = 0;
-        Changeset.eachAttribNumber(csOp.attribs, function(n)
-        {
-          attribKeys.push(pool.getAttribKey(n));
-          attribValues.push(pool.getAttribValue(n));
-        });
-        var undoBackToAttribs = cachedStrFunc(function(attribs)
-        {
-          var backAttribs = [];
-          for (var i = 0; i < attribKeys.length; i++)
-          {
-            var appliedKey = attribKeys[i];
-            var appliedValue = attribValues[i];
-            var oldValue = Changeset.attribsAttributeValue(attribs, appliedKey, pool);
-            if (appliedValue != oldValue)
-            {
-              backAttribs.push([appliedKey, oldValue]);
-            }
-          }
-          return Changeset.makeAttribsString('=', backAttribs, pool);
-        });
-        consumeAttribRuns(csOp.chars, function(len, attribs, endsLine)
-        {
-          builder.keep(len, endsLine ? 1 : 0, undoBackToAttribs(attribs));
-        });
-      }
-      else
-      {
-        skip(csOp.chars, csOp.lines);
-        builder.keep(csOp.chars, csOp.lines);
-      }
-    }
-    else if (csOp.opcode == '+')
-    {
-      builder.remove(csOp.chars, csOp.lines);
-    }
-    else if (csOp.opcode == '-')
-    {
-      var textBank = nextText(csOp.chars);
-      var textBankIndex = 0;
-      consumeAttribRuns(csOp.chars, function(len, attribs, endsLine)
-      {
-        builder.insert(textBank.substr(textBankIndex, len), attribs);
-        textBankIndex += len;
-      });
-    }
-  }
-
-  return Changeset.checkRep(builder.toString());
-};
-
-exports.Changeset = Changeset;
-exports.AttribPool = AttribPool;
diff --git a/static/js/linestylefilter.js b/static/js/linestylefilter.js
index d0b5bc6e8..4b4557247 100644
--- a/static/js/linestylefilter.js
+++ b/static/js/linestylefilter.js
@@ -28,7 +28,7 @@
 // requires: plugins
 // requires: undefined
 
-var Changeset = require('/easysync2').Changeset
+var Changeset = require('/Changeset');
 var plugins = require('/plugins').plugins;
 var map = require('/ace2_common').map;
 
diff --git a/static/js/linestylefilter_client.js b/static/js/linestylefilter_client.js
deleted file mode 100644
index f057e21a2..000000000
--- a/static/js/linestylefilter_client.js
+++ /dev/null
@@ -1,343 +0,0 @@
-/**
- * This code is mostly from the old Etherpad. Please help us to comment this code. 
- * This helps other people to understand this code better and helps them to improve it.
- * TL;DR COMMENTS ON THIS FILE ARE HIGHLY APPRECIATED
- */
-
-// DO NOT EDIT THIS FILE, edit infrastructure/ace/www/linestylefilter.js
-// THIS FILE IS ALSO AN APPJET MODULE: etherpad.collab.ace.linestylefilter
-/**
- * Copyright 2009 Google Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS-IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-// requires: easysync2.Changeset
-// requires: top
-// requires: plugins
-// requires: undefined
-
-var Changeset = require('/easysync2_client').Changeset
-var plugins = require('/plugins').plugins;
-var map = require('/ace2_common').map;
-
-var linestylefilter = {};
-
-linestylefilter.ATTRIB_CLASSES = {
-  'bold': 'tag:b',
-  'italic': 'tag:i',
-  'underline': 'tag:u',
-  'strikethrough': 'tag:s'
-};
-
-linestylefilter.getAuthorClassName = function(author)
-{
-  return "author-" + author.replace(/[^a-y0-9]/g, function(c)
-  {
-    if (c == ".") return "-";
-    return 'z' + c.charCodeAt(0) + 'z';
-  });
-};
-
-// lineLength is without newline; aline includes newline,
-// but may be falsy if lineLength == 0
-linestylefilter.getLineStyleFilter = function(lineLength, aline, textAndClassFunc, apool)
-{
-
-  var plugins_ = plugins;
-
-  if (lineLength == 0) return textAndClassFunc;
-
-  var nextAfterAuthorColors = textAndClassFunc;
-
-  var authorColorFunc = (function()
-  {
-    var lineEnd = lineLength;
-    var curIndex = 0;
-    var extraClasses;
-    var leftInAuthor;
-
-    function attribsToClasses(attribs)
-    {
-      var classes = '';
-      Changeset.eachAttribNumber(attribs, function(n)
-      {
-        var key = apool.getAttribKey(n);
-        if (key)
-        {
-          var value = apool.getAttribValue(n);
-          if (value)
-          {
-            if (key == 'author')
-            {
-              classes += ' ' + linestylefilter.getAuthorClassName(value);
-            }
-            else if (key == 'list')
-            {
-              classes += ' list:' + value;
-            }
-            else if (key == 'start')
-            {
-              classes += ' start:' + value;
-            }
-            else if (linestylefilter.ATTRIB_CLASSES[key])
-            {
-              classes += ' ' + linestylefilter.ATTRIB_CLASSES[key];
-            }
-            else
-            {
-              classes += plugins_.callHookStr("aceAttribsToClasses", {
-                linestylefilter: linestylefilter,
-                key: key,
-                value: value
-              }, " ", " ", "");
-            }
-          }
-        }
-      });
-      return classes.substring(1);
-    }
-
-    var attributionIter = Changeset.opIterator(aline);
-    var nextOp, nextOpClasses;
-
-    function goNextOp()
-    {
-      nextOp = attributionIter.next();
-      nextOpClasses = (nextOp.opcode && attribsToClasses(nextOp.attribs));
-    }
-    goNextOp();
-
-    function nextClasses()
-    {
-      if (curIndex < lineEnd)
-      {
-        extraClasses = nextOpClasses;
-        leftInAuthor = nextOp.chars;
-        goNextOp();
-        while (nextOp.opcode && nextOpClasses == extraClasses)
-        {
-          leftInAuthor += nextOp.chars;
-          goNextOp();
-        }
-      }
-    }
-    nextClasses();
-
-    return function(txt, cls)
-    {
-      while (txt.length > 0)
-      {
-        if (leftInAuthor <= 0)
-        {
-          // prevent infinite loop if something funny's going on
-          return nextAfterAuthorColors(txt, cls);
-        }
-        var spanSize = txt.length;
-        if (spanSize > leftInAuthor)
-        {
-          spanSize = leftInAuthor;
-        }
-        var curTxt = txt.substring(0, spanSize);
-        txt = txt.substring(spanSize);
-        nextAfterAuthorColors(curTxt, (cls && cls + " ") + extraClasses);
-        curIndex += spanSize;
-        leftInAuthor -= spanSize;
-        if (leftInAuthor == 0)
-        {
-          nextClasses();
-        }
-      }
-    };
-  })();
-  return authorColorFunc;
-};
-
-linestylefilter.getAtSignSplitterFilter = function(lineText, textAndClassFunc)
-{
-  var at = /@/g;
-  at.lastIndex = 0;
-  var splitPoints = null;
-  var execResult;
-  while ((execResult = at.exec(lineText)))
-  {
-    if (!splitPoints)
-    {
-      splitPoints = [];
-    }
-    splitPoints.push(execResult.index);
-  }
-
-  if (!splitPoints) return textAndClassFunc;
-
-  return linestylefilter.textAndClassFuncSplitter(textAndClassFunc, splitPoints);
-};
-
-linestylefilter.getRegexpFilter = function(regExp, tag)
-{
-  return function(lineText, textAndClassFunc)
-  {
-    regExp.lastIndex = 0;
-    var regExpMatchs = null;
-    var splitPoints = null;
-    var execResult;
-    while ((execResult = regExp.exec(lineText)))
-    {
-      if (!regExpMatchs)
-      {
-        regExpMatchs = [];
-        splitPoints = [];
-      }
-      var startIndex = execResult.index;
-      var regExpMatch = execResult[0];
-      regExpMatchs.push([startIndex, regExpMatch]);
-      splitPoints.push(startIndex, startIndex + regExpMatch.length);
-    }
-
-    if (!regExpMatchs) return textAndClassFunc;
-
-    function regExpMatchForIndex(idx)
-    {
-      for (var k = 0; k < regExpMatchs.length; k++)
-      {
-        var u = regExpMatchs[k];
-        if (idx >= u[0] && idx < u[0] + u[1].length)
-        {
-          return u[1];
-        }
-      }
-      return false;
-    }
-
-    var handleRegExpMatchsAfterSplit = (function()
-    {
-      var curIndex = 0;
-      return function(txt, cls)
-      {
-        var txtlen = txt.length;
-        var newCls = cls;
-        var regExpMatch = regExpMatchForIndex(curIndex);
-        if (regExpMatch)
-        {
-          newCls += " " + tag + ":" + regExpMatch;
-        }
-        textAndClassFunc(txt, newCls);
-        curIndex += txtlen;
-      };
-    })();
-
-    return linestylefilter.textAndClassFuncSplitter(handleRegExpMatchsAfterSplit, splitPoints);
-  };
-};
-
-
-linestylefilter.REGEX_WORDCHAR = /[\u0030-\u0039\u0041-\u005A\u0061-\u007A\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u00FF\u0100-\u1FFF\u3040-\u9FFF\uF900-\uFDFF\uFE70-\uFEFE\uFF10-\uFF19\uFF21-\uFF3A\uFF41-\uFF5A\uFF66-\uFFDC]/;
-linestylefilter.REGEX_URLCHAR = new RegExp('(' + /[-:@a-zA-Z0-9_.,~%+\/\\?=&#;()$]/.source + '|' + linestylefilter.REGEX_WORDCHAR.source + ')');
-linestylefilter.REGEX_URL = new RegExp(/(?:(?:https?|s?ftp|ftps|file|smb|afp|nfs|(x-)?man|gopher|txmt):\/\/|mailto:|www\.)/.source + linestylefilter.REGEX_URLCHAR.source + '*(?![:.,;])' + linestylefilter.REGEX_URLCHAR.source, 'g');
-linestylefilter.getURLFilter = linestylefilter.getRegexpFilter(
-linestylefilter.REGEX_URL, 'url');
-
-linestylefilter.textAndClassFuncSplitter = function(func, splitPointsOpt)
-{
-  var nextPointIndex = 0;
-  var idx = 0;
-
-  // don't split at 0
-  while (splitPointsOpt && nextPointIndex < splitPointsOpt.length && splitPointsOpt[nextPointIndex] == 0)
-  {
-    nextPointIndex++;
-  }
-
-  function spanHandler(txt, cls)
-  {
-    if ((!splitPointsOpt) || nextPointIndex >= splitPointsOpt.length)
-    {
-      func(txt, cls);
-      idx += txt.length;
-    }
-    else
-    {
-      var splitPoints = splitPointsOpt;
-      var pointLocInSpan = splitPoints[nextPointIndex] - idx;
-      var txtlen = txt.length;
-      if (pointLocInSpan >= txtlen)
-      {
-        func(txt, cls);
-        idx += txt.length;
-        if (pointLocInSpan == txtlen)
-        {
-          nextPointIndex++;
-        }
-      }
-      else
-      {
-        if (pointLocInSpan > 0)
-        {
-          func(txt.substring(0, pointLocInSpan), cls);
-          idx += pointLocInSpan;
-        }
-        nextPointIndex++;
-        // recurse
-        spanHandler(txt.substring(pointLocInSpan), cls);
-      }
-    }
-  }
-  return spanHandler;
-};
-
-linestylefilter.getFilterStack = function(lineText, textAndClassFunc, browser)
-{
-  var func = linestylefilter.getURLFilter(lineText, textAndClassFunc);
-
-  var plugins_ = plugins;
-
-  var hookFilters = plugins_.callHook("aceGetFilterStack", {
-    linestylefilter: linestylefilter,
-    browser: browser
-  });
-  map(hookFilters, function(hookFilter)
-  {
-    func = hookFilter(lineText, func);
-  });
-
-  if (browser !== undefined && browser.msie)
-  {
-    // IE7+ will take an e-mail address like <foo@bar.com> and linkify it to foo@bar.com.
-    // We then normalize it back to text with no angle brackets.  It's weird.  So always
-    // break spans at an "at" sign.
-    func = linestylefilter.getAtSignSplitterFilter(
-    lineText, func);
-  }
-  return func;
-};
-
-// domLineObj is like that returned by domline.createDomLine
-linestylefilter.populateDomLine = function(textLine, aline, apool, domLineObj)
-{
-  // remove final newline from text if any
-  var text = textLine;
-  if (text.slice(-1) == '\n')
-  {
-    text = text.substring(0, text.length - 1);
-  }
-
-  function textAndClassFunc(tokenText, tokenClass)
-  {
-    domLineObj.appendSpan(tokenText, tokenClass);
-  }
-
-  var func = linestylefilter.getFilterStack(text, textAndClassFunc);
-  func = linestylefilter.getLineStyleFilter(text.length, aline, func, apool);
-  func(text, '');
-};
-
-exports.linestylefilter = linestylefilter;
diff --git a/static/js/pad.js b/static/js/pad.js
index 9dab9c618..eb480080f 100644
--- a/static/js/pad.js
+++ b/static/js/pad.js
@@ -46,47 +46,9 @@ var padsavedrevs = require('/pad_savedrevs').padsavedrevs;
 var paduserlist = require('/pad_userlist').paduserlist;
 var padutils = require('/pad_utils').padutils;
 
-function createCookie(name, value, days, path)
-{
-  if (days)
-  {
-    var date = new Date();
-    date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
-    var expires = "; expires=" + date.toGMTString();
-  }
-  else var expires = "";
-  
-  if(!path)
-    path = "/";
-  
-  document.cookie = name + "=" + value + expires + "; path=" + path;
-}
-
-function readCookie(name)
-{
-  var nameEQ = name + "=";
-  var ca = document.cookie.split(';');
-  for (var i = 0; i < ca.length; i++)
-  {
-    var c = ca[i];
-    while (c.charAt(0) == ' ') c = c.substring(1, c.length);
-    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length, c.length);
-  }
-  return null;
-}
-
-function randomString()
-{
-  var chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
-  var string_length = 20;
-  var randomstring = '';
-  for (var i = 0; i < string_length; i++)
-  {
-    var rnum = Math.floor(Math.random() * chars.length);
-    randomstring += chars.substring(rnum, rnum + 1);
-  }
-  return "t." + randomstring;
-}
+var createCookie = require('/pad_utils').createCookie;
+var readCookie = require('/pad_utils').readCookie;
+var randomString = require('/pad_utils').randomString;
 
 function getParams()
 {
@@ -210,7 +172,7 @@ function handshake()
     var token = readCookie("token");
     if (token == null)
     {
-      token = randomString();
+      token = "t." + randomString();
       createCookie("token", token, 60);
     }
     
diff --git a/static/js/pad_utils.js b/static/js/pad_utils.js
index 071185a80..fb538211f 100644
--- a/static/js/pad_utils.js
+++ b/static/js/pad_utils.js
@@ -20,17 +20,58 @@
  * limitations under the License.
  */
 
+var Security = require('/security');
+
+/**
+ * Generates a random String with the given length. Is needed to generate the Author, Group, readonly, session Ids
+ */
+
+function randomString(len)
+{
+  var chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+  var randomstring = '';
+  len = len || 20
+  for (var i = 0; i < len; i++)
+  {
+    var rnum = Math.floor(Math.random() * chars.length);
+    randomstring += chars.substring(rnum, rnum + 1);
+  }
+  return randomstring;
+}
+
+function createCookie(name, value, days, path)
+{
+  if (days)
+  {
+    var date = new Date();
+    date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
+    var expires = "; expires=" + date.toGMTString();
+  }
+  else var expires = "";
+
+  if(!path)
+    path = "/";
+
+  document.cookie = name + "=" + value + expires + "; path=" + path;
+}
+
+function readCookie(name)
+{
+  var nameEQ = name + "=";
+  var ca = document.cookie.split(';');
+  for (var i = 0; i < ca.length; i++)
+  {
+    var c = ca[i];
+    while (c.charAt(0) == ' ') c = c.substring(1, c.length);
+    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length, c.length);
+  }
+  return null;
+}
+
 var padutils = {
   escapeHtml: function(x)
   {
-    return String(x).replace(/[&"<>]/g, function (c) {
-      return {
-        '&': '&amp;',
-        '"': '&quot;',
-        '<': '&lt;',
-        '>': '&gt;'
-      }[c] || c;
-    });
+    return Security.escapeHTML(String(x));
   },
   uniqueId: function()
   {
@@ -159,7 +200,7 @@ var padutils = {
     {
       if (i > idx)
       {
-        pieces.push(padutils.escapeHtml(text.substring(idx, i)));
+        pieces.push(Security.escapeHTML(text.substring(idx, i)));
         idx = i;
       }
     }
@@ -170,7 +211,7 @@ var padutils = {
         var startIndex = urls[j][0];
         var href = urls[j][1];
         advanceTo(startIndex);
-        pieces.push('<a ', (target ? 'target="' + target + '" ' : ''), 'href="', padutils.escapeHtml(href), '">');
+        pieces.push('<a ', (target ? 'target="' + Security.escapeHTMLAttribute(target) + '" ' : ''), 'href="', Security.escapeHTMLAttribute(href), '">');
         advanceTo(startIndex + href.length);
         pieces.push('</a>');
       }
@@ -481,4 +522,7 @@ padutils.setupGlobalExceptionHandler = setupGlobalExceptionHandler;
 
 padutils.binarySearch = require('/ace2_common').binarySearch;
 
+exports.randomString = randomString;
+exports.createCookie = createCookie;
+exports.readCookie = readCookie;
 exports.padutils = padutils;
diff --git a/static/js/security.js b/static/js/security.js
new file mode 100644
index 000000000..6f42d0516
--- /dev/null
+++ b/static/js/security.js
@@ -0,0 +1,54 @@
+/**
+ * Copyright 2009 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS-IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+var HTML_ENTITY_MAP = {
+  '&': '&amp;'
+, '<': '&lt;'
+, '>': '&gt;'
+, '"': '&quot;'
+, "'": '&#x27;'
+, '/': '&#x2F;'
+};
+
+// OSWASP Guidlines: &, <, >, ", ' plus forward slash.
+var HTML_CHARACTERS_EXPRESSION = /[&"'<>\/]/g;
+function escapeHTML(text) {
+  return text && text.replace(HTML_CHARACTERS_EXPRESSION, function (c) {
+    return HTML_ENTITY_MAP[c] || c;
+  });
+}
+
+// OSWASP Guidlines: escape all non alphanumeric characters in ASCII space.
+var HTML_ATTRIBUTE_CHARACTERS_EXPRESSION =
+    /[\x00-\x2F\x3A-\x40\5B-\x60\x7B-\xFF]/g;
+function escapeHTMLAttribute(text) {
+  return text && text.replace(HTML_ATTRIBUTE_CHARACTERS_EXPRESSION, function (c) {
+    return "&#x" + ('00' + c.charCodeAt(0).toString(16)).slice(-2) + ";";
+  });
+};
+
+// OSWASP Guidlines: escape all non alphanumeric characters in ASCII space.
+var JAVASCRIPT_CHARACTERS_EXPRESSION =
+    /[\x00-\x2F\x3A-\x40\5B-\x60\x7B-\xFF]/g;
+function escapeJavaScriptData(text) {
+  return text && text.replace(JAVASCRIPT_CHARACTERS_EXPRESSION, function (c) {
+    return "\\x" + ('00' + c.charCodeAt(0).toString(16)).slice(-2);
+  });
+}
+
+exports.escapeHTML = escapeHTML;
+exports.escapeHTMLAttribute = escapeHTMLAttribute;
+exports.escapeJavaScriptData = escapeJavaScriptData;
diff --git a/static/js/timeslider.js b/static/js/timeslider.js
index d2fce8fd7..143ef3281 100644
--- a/static/js/timeslider.js
+++ b/static/js/timeslider.js
@@ -26,39 +26,9 @@ require('/jquery');
 JSON = require('/json2');
 require('/undo-xpopup');
 
-function createCookie(name,value,days)
-{
-  if (days) {
-    var date = new Date();
-    date.setTime(date.getTime()+(days*24*60*60*1000));
-    var expires = "; expires="+date.toGMTString();
-  }
-  else var expires = "";
-  document.cookie = name+"="+value+expires+"; path=/";
-}
-
-function readCookie(name)
-{
-  var nameEQ = name + "=";
-  var ca = document.cookie.split(';');
-  for(var i=0;i < ca.length;i++) {
-    var c = ca[i];
-    while (c.charAt(0)==' ') c = c.substring(1,c.length);
-    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
-  }
-  return null;
-}
-
-function randomString() {
-  var chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
-  var string_length = 20;
-  var randomstring = '';
-  for (var i=0; i<string_length; i++) {
-    var rnum = Math.floor(Math.random() * chars.length);
-    randomstring += chars.substring(rnum,rnum+1);
-  }
-  return "t." + randomstring;
-}
+var createCookie = require('/pad_utils').createCookie;
+var readCookie = require('/pad_utils').readCookie;
+var randomString = require('/pad_utils').randomString;
 
 var socket, token, padId, export_links;
 
@@ -79,7 +49,7 @@ function init() {
     token = readCookie("token");
     if(token == null)
     {
-      token = randomString();
+      token = "t." + randomString();
       createCookie("token", token, 60);
     }
 
diff --git a/static/js/undomodule.js b/static/js/undomodule.js
index aff41a70c..886cbdf0a 100644
--- a/static/js/undomodule.js
+++ b/static/js/undomodule.js
@@ -20,7 +20,7 @@
  * limitations under the License.
  */
 
-var Changeset = require('/easysync2').Changeset;
+var Changeset = require('/Changeset');
 var extend = require('/ace2_common').extend;
 
 var undoModule = (function()