protect session data with pwg_db_real_escape_string

git-svn-id: http://piwigo.org/svn/trunk@20281 68402e56-0260-453c-a942-63ccdbb3a9ee
feature:2823 Add triggers for login system 

git-svn-id: http://piwigo.org/svn/trunk@20282 68402e56-0260-453c-a942-63ccdbb3a9ee
[trunk_admin] Update ro_RO, thanks to : norboo

git-svn-id: http://piwigo.org/svn/trunk@20287 68402e56-0260-453c-a942-63ccdbb3a9ee