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/branches/branch-1_5@1003 68402e56-0260-453c-a942-63ccdbb3a9ee

admin/picture_modify.php

@@ -195,12 +195,10 @@ $template->set_filenames(
 $template->assign_vars(
   array(
     'U_SYNC' =>
-      add_session_id(
         PHPWG_ROOT_PATH.'admin.php?page=picture_modify'.
         '&image_id='.$_GET['image_id'].
         (isset($_GET['cat_id']) ? '&cat_id='.$_GET['cat_id'] : '').
-        '&sync_metadata=1'
-        ),
+        '&sync_metadata=1',
     
     'PATH'=>$row['path'],
     
@@ -230,10 +228,8 @@ $template->assign_vars(
         stripslashes($_POST['description']) : @$row['comment'],
   
     'F_ACTION' =>
-      add_session_id(
         PHPWG_ROOT_PATH.'admin.php'
         .get_query_string_diff(array('sync_metadata'))
-        )
     )
   );