changing esc_url to esc_attr for dashicon support

git-svn-id: https://plugins.svn.wordpress.org/custom-post-type-ui/trunk@939390 b8457f37-d9ea-0310-8a92-e5e31aec5664
updating version numbers and minimum requirements

git-svn-id: https://plugins.svn.wordpress.org/custom-post-type-ui/trunk@939391 b8457f37-d9ea-0310-8a92-e5e31aec5664
version update notes and version numbers

git-svn-id: https://plugins.svn.wordpress.org/custom-post-type-ui/trunk@939393 b8457f37-d9ea-0310-8a92-e5e31aec5664