js: Name all the timeouts and idles

With very uninventive names. Names now, good names later.

https://bugzilla.gnome.org/show_bug.cgi?id=727983

js/gdm/util.js

@@ -252,6 +252,7 @@ const ShellUserVerifier = new Lang.Class({
                                                            this._queueMessageTimeout();
                                                            return GLib.SOURCE_REMOVE;
                                                        }));
+        GLib.Source.set_name_by_id(this._messageQueueTimeoutId, '[gnome-shell] this._queueMessageTimeout');
     },
 
     _queueMessage: function(message, messageType) {