Corrections

git-svn-id: https://plugins.svn.wordpress.org/single-categories/trunk@999833 b8457f37-d9ea-0310-8a92-e5e31aec5664
Make version compatible up to 4? Tests

git-svn-id: https://plugins.svn.wordpress.org/single-categories/trunk@999836 b8457f37-d9ea-0310-8a92-e5e31aec5664