Uploading version 2.1.1, translated to Spanish, Catalan, and Serbian

git-svn-id: https://plugins.svn.wordpress.org/nelio-related-posts/trunk@1043434 b8457f37-d9ea-0310-8a92-e5e31aec5664
Updating title in readme

git-svn-id: https://plugins.svn.wordpress.org/nelio-related-posts/trunk@1043441 b8457f37-d9ea-0310-8a92-e5e31aec5664