Author: Helen Foster
MDL-23221 help string rewording
http://git.moodle.org/gw?p=moodle.git;a=commit;h=c605baf80208b9580c0c436a1f8833d8377a309b
http://github.com/moodle/moodle/commit/c605baf80208b9580c0c436a1f8833d8377a309b
+ 2.0 en [permission_help,core_role]