1.4.20, see readme for changelog.

git-svn-id: https://plugins.svn.wordpress.org/wordpress-seo/trunk@822957 b8457f37-d9ea-0310-8a92-e5e31aec5664
1.4.21, see readme for changelog.

git-svn-id: https://plugins.svn.wordpress.org/wordpress-seo/trunk@823045 b8457f37-d9ea-0310-8a92-e5e31aec5664