added: SessionContainer special container used by SessionManager

sessions are indexed by id and time (last used time)
changed: old sessions are deleted
       parameter: session_max_iddle in the config file
added: function 'who'


git-svn-id: svn://ttmath.org/publicrep/cmslu/trunk@483 e52654a7-88a9-db11-a3e9-0013d4bc506e

core/session.cpp

@@ -15,6 +15,10 @@ Session::Session()
 	Clear();
 	
 	time = std::time(0);
+	tm_time = *std::localtime(&time);
+	
+	last_time = time;
+	tm_last_time = tm_time;
 }