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/misc.h

@@ -31,6 +31,7 @@ void SetUrlFromSubject(Item & item);
 
 void HtmlEscape(std::ostringstream & out, const std::string & in);
 std::string HtmlEscape(const std::string & in);
+const char * DateToStr(int month, int day, int hour, int min, int sec);
 
 
 #endif