Feature : Saved status and warning msg

Added saved status (*) next to title when a Piskel is updated.
Upon saving, the * disappears.

If the workspace contains an unsaved piskel when leaving the application a
message will be displayed to the user, using onbeforeunload.

This logic should also be used everywhere we display a confirm message
before a navigation.

js/controller/settings/SaveController.js

@@ -95,6 +95,7 @@
   ns.SaveController.prototype.onSaveSuccess_ = function () {
     $.publish(Events.CLOSE_SETTINGS_DRAWER);
     $.publish(Events.SHOW_NOTIFICATION, [{"content": "Successfully saved !"}]);
+    $.publish(Events.PISKEL_SAVED);
   };
 
   ns.SaveController.prototype.onSaveError_ = function (status) {