Correct return value for get_role() and WP_Roles::get_role(). props tivnet. fixes #24607.

git-svn-id: http://core.svn.wordpress.org/trunk@24491 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Partially revert [24459] and only flush insert_id on the next insert or replace query, as we had been doing before. (Yes, this is not how mysql_insert_id() works.)



git-svn-id: http://core.svn.wordpress.org/trunk@24494 1a063a9b-81f0-0310-95a4-ce76da25c4cd