Add user_search_columns filter to WP_User_Query::prepare_query().

props aaroncampbell.
fixes #16366.



git-svn-id: http://core.svn.wordpress.org/trunk@24056 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Return false in get_post_format() if the post does not exist.

props adamsilverstein, ericlewis.
fixes #23255.



git-svn-id: http://core.svn.wordpress.org/trunk@24057 1a063a9b-81f0-0310-95a4-ce76da25c4cd