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/core/image.cpp

@@ -498,7 +498,8 @@ void Image::ImageSavedCorrectly()
 			{
 				// IMPROVEME we need a separate model_connector for this thread
 				Lock();
-				file_work.update(false, false);
+				file_work.propagate_connector();
+				file_work.item_content.update(false);
 				//db->EditHasThumbById(true, file_work.id);
 			}
 		}