added a rate msg metabox

git-svn-id: https://plugins.svn.wordpress.org/nextgen-facebook/trunk@771828 b8457f37-d9ea-0310-8a92-e5e31aec5664
added check mark image

git-svn-id: https://plugins.svn.wordpress.org/nextgen-facebook/trunk@771832 b8457f37-d9ea-0310-8a92-e5e31aec5664