changed class names

git-svn-id: https://plugins.svn.wordpress.org/plainmail/trunk@773015 b8457f37-d9ea-0310-8a92-e5e31aec5664
updated readme

git-svn-id: https://plugins.svn.wordpress.org/plainmail/trunk@773016 b8457f37-d9ea-0310-8a92-e5e31aec5664