version 1.4.7 - improved default checkbox css and added WP check in views to prevent direct access

git-svn-id: https://plugins.svn.wordpress.org/mailchimp-for-wp/trunk@814619 b8457f37-d9ea-0310-8a92-e5e31aec5664
removed nag from readme

git-svn-id: https://plugins.svn.wordpress.org/mailchimp-for-wp/trunk@814620 b8457f37-d9ea-0310-8a92-e5e31aec5664