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/mkdir.cpp

@@ -90,6 +90,7 @@ return true;
 
 void Mkdir::PostFunMkdir(bool add_to_dir_tab, int privileges)
 {
+	cur->request->item.set_connector(model_connector);
 	functions->ReadItem(cur->request->item, Item::dir);
 	functions->SetUser(cur->request->item);
 	cur->request->item.item_content.privileges = privileges;