Fix duplicate theme bug, localise strings

git-svn-id: https://plugins.svn.wordpress.org/megamenu/trunk@952938 b8457f37-d9ea-0310-8a92-e5e31aec5664
Add lang files

git-svn-id: https://plugins.svn.wordpress.org/megamenu/trunk@952939 b8457f37-d9ea-0310-8a92-e5e31aec5664