readme changes, changed version scheme

git-svn-id: http://plugins.svn.wordpress.org/asynchronous-javascript/trunk@654934 b8457f37-d9ea-0310-8a92-e5e31aec5664
starting compatability list, seo

git-svn-id: http://plugins.svn.wordpress.org/asynchronous-javascript/trunk@654955 b8457f37-d9ea-0310-8a92-e5e31aec5664
merged