new tag 6.7.4

git-svn-id: https://plugins.svn.wordpress.org/nextgen-facebook/trunk@768299 b8457f37-d9ea-0310-8a92-e5e31aec5664
stable tag 6.7.4

git-svn-id: https://plugins.svn.wordpress.org/nextgen-facebook/trunk@768305 b8457f37-d9ea-0310-8a92-e5e31aec5664