Author: Andrew Nicols
MDL-62079 core_filters: Implement null provider
http://git.moodle.org/gw?p=moodle.git;a=commit;h=e055b85a0f576f6fe814ff4385b24253c2beddd3
http://github.com/moodle/moodle/commit/e055b85a0f576f6fe814ff4385b24253c2beddd3
+ 3.5 en [privacy:reason,core_filters]