Author: Andrew Nicols
MDL-55528 admin: Add a new generic admin setting type
http://git.moodle.org/gw?p=moodle.git;a=commit;h=29ce0058629852145eff342db44468ab6c777475
http://github.com/moodle/moodle/commit/29ce0058629852145eff342db44468ab6c777475
+ 3.3 en [fileconversioncleanuptask,core_admin]
+ 3.3 en [isenabled,core_plugin]