MacOSX/Framework/VLCMediaList.m: Don't forget to listen to WillAdd/WillDelete media list event.

Sources/VLCMediaList.m

@@ -307,7 +307,9 @@ static void HandleMediaListWillDeleteItem(const libvlc_event_t *event, void *use
 
     libvlc_event_manager_t *p_em = libvlc_media_list_event_manager( p_mlist, &p_e );
     libvlc_event_attach( p_em, libvlc_MediaListItemAdded,   HandleMediaListItemAdded,   self, &p_e );
+    libvlc_event_attach( p_em, libvlc_MediaListWillAddItem, HandleMediaListWillAddItem, self, &p_e );
     libvlc_event_attach( p_em, libvlc_MediaListItemDeleted, HandleMediaListItemDeleted, self, &p_e );
+    libvlc_event_attach( p_em, libvlc_MediaListWillDeleteItem, HandleMediaListWillDeleteItem, self, &p_e );
     [self unlock];
     
     quit_on_exception( &p_e );