added filters to add data-ngfb-wp-pid and data-ngfb-ngg-pid attributes to a/img/div

git-svn-id: https://plugins.svn.wordpress.org/nextgen-facebook/trunk@752405 b8457f37-d9ea-0310-8a92-e5e31aec5664
readme update

git-svn-id: https://plugins.svn.wordpress.org/nextgen-facebook/trunk@752408 b8457f37-d9ea-0310-8a92-e5e31aec5664