updates for new version 1.2.0

git-svn-id: https://plugins.svn.wordpress.org/affilinker/trunk@757125 b8457f37-d9ea-0310-8a92-e5e31aec5664
readme update for tested version 3.6

git-svn-id: https://plugins.svn.wordpress.org/affilinker/trunk@757130 b8457f37-d9ea-0310-8a92-e5e31aec5664