updated help. Deploy 1.6.3

git-svn-id: https://plugins.svn.wordpress.org/postie/trunk@1001517 b8457f37-d9ea-0310-8a92-e5e31aec5664
prep 1.6.4

git-svn-id: https://plugins.svn.wordpress.org/postie/trunk@1001520 b8457f37-d9ea-0310-8a92-e5e31aec5664