changed: DirContainer - uses std::list instead of std::vector as the main container

we do not have to rebuild indexes after deleting some items
added:   DirContainer::DelById(long id)
changed: Dirs::CheckRootDir() addes the root dir if there is no one
added:   Dirs::DeleteDir(long id) - deletes specified directory (and its contents)
         (from the cache and the database)
added:   Db::DelDirById(long id) - deletes a dir from the database 
         and its first children
added:   standard function rm can delete directories


git-svn-id: svn://ttmath.org/publicrep/cmslu/trunk@487 e52654a7-88a9-db11-a3e9-0013d4bc506e

core/session.cpp

@@ -31,6 +31,8 @@ void Session::Clear()
 	done_status = Error::ok;
 	item.Clear();
 	done_timer = 0;
+	
+	dir_old.clear();
 }
 
 
@@ -72,5 +74,8 @@ void Session::CheckTimers()
 	}
 }
 
-
-
+void Session::IncrementTimersIfExist()
+{
+	if( done_timer != 0 )
+		++done_timer;
+}