registration form changes

git-svn-id: https://plugins.svn.wordpress.org/affiliates/trunk@917847 b8457f37-d9ea-0310-8a92-e5e31aec5664
tagged 2.6.2

git-svn-id: https://plugins.svn.wordpress.org/affiliates/trunk@917849 b8457f37-d9ea-0310-8a92-e5e31aec5664