Tagging v2.4 in trunk

git-svn-id: https://plugins.svn.wordpress.org/private-content/trunk@863561 b8457f37-d9ea-0310-8a92-e5e31aec5664
Updated readme

git-svn-id: https://plugins.svn.wordpress.org/private-content/trunk@863569 b8457f37-d9ea-0310-8a92-e5e31aec5664
Updated readme

git-svn-id: https://plugins.svn.wordpress.org/private-content/trunk@863570 b8457f37-d9ea-0310-8a92-e5e31aec5664