Author: Charles Fulton
MDL-45113 auth: add is_configured method and convert auth_db to use it
http://git.moodle.org/gw?p=moodle.git;a=commit;h=e5ca803a4053c395de93149ab45afdf995c16074
http://github.com/moodle/moodle/commit/e5ca803a4053c395de93149ab45afdf995c16074
+ 2.9 en [auth_notconfigured,core_auth]