remove old WP Ajax Edit Comments support

git-svn-id: https://plugins.svn.wordpress.org/cforms2/trunk@1022470 b8457f37-d9ea-0310-8a92-e5e31aec5664
replace Subscribe To Comments support with a more general approach

git-svn-id: https://plugins.svn.wordpress.org/cforms2/trunk@1022471 b8457f37-d9ea-0310-8a92-e5e31aec5664