Add missing inline descriptions. see #19067.

git-svn-id: http://core.svn.wordpress.org/trunk@23437 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Deprecate get_user_id_from_string() in favor of get_user_by( $field ) where $field is 'email' or 'login'. props SergeyBiryukov. fixes #23190.



git-svn-id: http://core.svn.wordpress.org/trunk@23438 1a063a9b-81f0-0310-95a4-ce76da25c4cd