Compatibility with WordPress 4.0

git-svn-id: https://plugins.svn.wordpress.org/full-screen-background-images/trunk@974038 b8457f37-d9ea-0310-8a92-e5e31aec5664
Compatibility with WordPress 4.0

git-svn-id: https://plugins.svn.wordpress.org/full-screen-background-images/trunk@974040 b8457f37-d9ea-0310-8a92-e5e31aec5664