IE doesn't know indexOf for arrays FS#2381

this fixes another IE javascript problem in edit mode

lib/scripts/editor.js

@@ -130,7 +130,7 @@ var dw_editor = {
      * @param event e - the key press event object
      */
     keyHandler: function(e){
-        if([8, 13, 32].indexOf(e.keyCode) === -1) {
+        if(jQuery.inArray(e.keyCode,[8, 13, 32]) === -1) {
             return;
         }
         var selection = getSelection(this);