Improve security of sessions:

- use only cookies to store session id on client side
- use default php session system with database handler to store sessions on server side

git-svn-id: http://piwigo.org/svn/trunk@1004 68402e56-0260-453c-a942-63ccdbb3a9ee

admin/cat_perm.php

@@ -207,10 +207,7 @@ $template->assign_vars(
         'admin.php?page=cat_modify&cat_id='
         ),
     'U_HELP' => PHPWG_ROOT_PATH.'/popuphelp.php?page=cat_perm',
-    'F_ACTION' =>
-      add_session_id(
-        PHPWG_ROOT_PATH.'admin.php?page=cat_perm&cat='.$page['cat']
-        )
+    'F_ACTION' => PHPWG_ROOT_PATH.'admin.php?page=cat_perm&cat='.$page['cat']
     )
   );