Included lib/xmlize.php to use it intensively

restoring mods.
Perhaps, in a future, the rest of the reading must be
xmlized too !!! (users, course_info, header...), but not now.

backup/restore.php

@@ -14,6 +14,7 @@
     //Units used
     require_once ("$moodle_home/config.php");
     require_once ("$moodle_home/version.php");
+    require_once ("$moodle_home/lib/xmlize.php");
     require_once ("backup_version.php");
     require_once ("db/backup_$CFG->dbtype.php");
     require_once ("lib.php");