CVE-2013-2249

      mod_session_dbd: Make sure that dirty flag is respected when saving 
sessions, and ensure the session ID is changed each time the session 
changes.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1488158 13f79535-47bb-0310-9956-ffa450edef68