Author: Andrew Hancox
MDL-26935 course: Require course:renameroles to rename roles.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=502336f215494c25477cbef53392bbdd1f28657e
http://github.com/moodle/moodle/commit/502336f215494c25477cbef53392bbdd1f28657e
+ 3.1 en [course:renameroles,core_role]