Merged security fix

git-svn-id: https://plugins.svn.wordpress.org/gigya-socialize-for-wordpress/trunk@780743 b8457f37-d9ea-0310-8a92-e5e31aec5664
Added required fields support

git-svn-id: https://plugins.svn.wordpress.org/gigya-socialize-for-wordpress/trunk@780744 b8457f37-d9ea-0310-8a92-e5e31aec5664
Added uninstall hook

git-svn-id: https://plugins.svn.wordpress.org/gigya-socialize-for-wordpress/trunk@780746 b8457f37-d9ea-0310-8a92-e5e31aec5664