Added Language features and .pot file

git-svn-id: https://plugins.svn.wordpress.org/wp-google-plus-one-button/trunk@944306 b8457f37-d9ea-0310-8a92-e5e31aec5664
Features updated on Readme file.

git-svn-id: https://plugins.svn.wordpress.org/wp-google-plus-one-button/trunk@944307 b8457f37-d9ea-0310-8a92-e5e31aec5664