1.5.3 release

git-svn-id: https://plugins.svn.wordpress.org/ultimate-maintenance-mode/trunk@817720 b8457f37-d9ea-0310-8a92-e5e31aec5664
added language files

git-svn-id: https://plugins.svn.wordpress.org/ultimate-maintenance-mode/trunk@817722 b8457f37-d9ea-0310-8a92-e5e31aec5664