+void folder_update_item (FolderItem *item,
+ gboolean contentchange);
+void folder_update_items_when_required (gboolean contentchange);
+void folder_update_item_recursive (FolderItem *item,
+ gboolean update_summary);
+gint folder_item_update_callback_register(FolderItemUpdateFunc func,
+ gpointer data);
+void folder_item_update_callback_unregister(gint id);
+