Updated codemirror to v4.12.

Did a lot of cleanup to limit the size of the plugin.
I kept the emmet plugin.

applications/admin/static/codemirror/addon/fold/foldcode.js

@@ -1,3 +1,6 @@
+// CodeMirror, copyright (c) by Marijn Haverbeke and others
+// Distributed under an MIT license: http://codemirror.net/LICENSE
+
 (function(mod) {
   if (typeof exports == "object" && typeof module == "object") // CommonJS
     mod(require("../../lib/codemirror"));
@@ -9,10 +12,14 @@
   "use strict";
 
   function doFold(cm, pos, options, force) {
-    var finder = options && (options.call ? options : options.rangeFinder);
-    if (!finder) finder = CodeMirror.fold.auto;
+    if (options && options.call) {
+      var finder = options;
+      options = null;
+    } else {
+      var finder = getOption(cm, options, "rangeFinder");
+    }
     if (typeof pos == "number") pos = CodeMirror.Pos(pos, 0);
-    var minSize = options && options.minFoldSize || 0;
+    var minSize = getOption(cm, options, "minFoldSize");
 
     function getRange(allowFolded) {
       var range = finder(cm, pos);
@@ -29,14 +36,17 @@
     }
 
     var range = getRange(true);
-    if (options && options.scanUp) while (!range && pos.line > cm.firstLine()) {
+    if (getOption(cm, options, "scanUp")) while (!range && pos.line > cm.firstLine()) {
       pos = CodeMirror.Pos(pos.line - 1, 0);
       range = getRange(false);
     }
     if (!range || range.cleared || force === "unfold") return;
 
-    var myWidget = makeWidget(options);
-    CodeMirror.on(myWidget, "mousedown", function() { myRange.clear(); });
+    var myWidget = makeWidget(cm, options);
+    CodeMirror.on(myWidget, "mousedown", function(e) {
+      myRange.clear();
+      CodeMirror.e_preventDefault(e);
+    });
     var myRange = cm.markText(range.from, range.to, {
       replacedWith: myWidget,
       clearOnEnter: true,
@@ -48,8 +58,8 @@
     CodeMirror.signal(cm, "fold", cm, range.from, range.to);
   }
 
-  function makeWidget(options) {
-    var widget = (options && options.widget) || "\u2194";
+  function makeWidget(cm, options) {
+    var widget = getOption(cm, options, "widget");
     if (typeof widget == "string") {
       var text = document.createTextNode(widget);
       widget = document.createElement("span");
@@ -114,4 +124,26 @@
       if (cur) return cur;
     }
   });
+
+  var defaultOptions = {
+    rangeFinder: CodeMirror.fold.auto,
+    widget: "\u2194",
+    minFoldSize: 0,
+    scanUp: false
+  };
+
+  CodeMirror.defineOption("foldOptions", null);
+
+  function getOption(cm, options, name) {
+    if (options && options[name] !== undefined)
+      return options[name];
+    var editorOptions = cm.options.foldOptions;
+    if (editorOptions && editorOptions[name] !== undefined)
+      return editorOptions[name];
+    return defaultOptions[name];
+  }
+
+  CodeMirror.defineExtension("foldOption", function(options, name) {
+    return getOption(this, options, name);
+  });
 });