Made slotObjectUpdated public, as needed by python scripting

Core/Core.hh

@@ -416,11 +416,12 @@ signals:
     /** @name Slots called by the plugins
     * @{ */
    //===========================================================================
-   private slots :
+   public slots :
 
       /// Called by the plugins if they changed something in the object list (deleted, added, or other property changes)
       void slotObjectUpdated(int _identifier, const UpdateType& _type = UPDATE_ALL);
 
+   private slots:
       /// Called when a plugin changes the visibility of an object
       void slotVisibilityChanged(int _id);