Version 3.0 is now beta

git-svn-id: https://plugins.svn.wordpress.org/varnish-http-purge/trunk@761505 b8457f37-d9ea-0310-8a92-e5e31aec5664
Screenshot rename, adding to readme

git-svn-id: https://plugins.svn.wordpress.org/varnish-http-purge/trunk@761506 b8457f37-d9ea-0310-8a92-e5e31aec5664