Port everything to class framework

The last patch in the sequence. Every place that was previously
setting prototype has been ported to Lang.Class, to make code more
concise and allow for better toString().

https://bugzilla.gnome.org/show_bug.cgi?id=664436

js/ui/xdndHandler.js

@@ -6,11 +6,9 @@ const Shell = imports.gi.Shell;
 const Signals = imports.signals;
 const DND = imports.ui.dnd;
 
-function XdndHandler() {
-    this._init();
-}
+const XdndHandler = new Lang.Class({
+    Name: 'XdndHandler',
 
-XdndHandler.prototype = {
     _init: function() {
         // Used to display a clone of the cursor window when the
         // window group is hidden (like it happens in the overview)
@@ -125,6 +123,6 @@ XdndHandler.prototype = {
                 pickedActor = pickedActor.get_parent();
         }
     }
-}
+});
 
 Signals.addSignalMethods(XdndHandler.prototype);