removed from Item: update() and save() methods which take the 'url_was_changed' argument

and added ItemModelData (based on morm::ModelData) class which has 'prepare_unique_url' field,
an object of this class is passed to update(), insert() and save() methods

fixed: Dirs::CheckRootDir(): update should update childs too (privileges)

WIP: #4

winixd/functions/privchanger.cpp

@@ -133,8 +133,10 @@ void PrivChanger::ChangePriv(Item & item, long user_id, long group_id, int privi
 			return;
 	}
 
+	item.propagate_connector();
+
 	//cur->request->status = db->EditPrivById(item, item.id);
-	if( !item.update(false, true) )
+	if( !item.item_content.update() )
 	{
 		// IMPROVEME put some log here, and slog too
 	}