Improved help section and layout for WP 3.9

git-svn-id: https://plugins.svn.wordpress.org/simple-links/trunk@884796 b8457f37-d9ea-0310-8a92-e5e31aec5664
Adding updated language file and updated readme.txt for new version

git-svn-id: https://plugins.svn.wordpress.org/simple-links/trunk@884798 b8457f37-d9ea-0310-8a92-e5e31aec5664