Uploading 3.1.0.

git-svn-id: https://plugins.svn.wordpress.org/admin-page-framework/trunk@950620 b8457f37-d9ea-0310-8a92-e5e31aec5664
Marked 3.1.0 as stable.

git-svn-id: https://plugins.svn.wordpress.org/admin-page-framework/trunk@950623 b8457f37-d9ea-0310-8a92-e5e31aec5664