Author: Katie Ransom
MDL-83840 course: add warning when hiding category
http://git.moodle.org/gw?p=moodle.git;a=commit;h=8c355f1f1c895739a4c404bcc2d500d166344bfc
http://github.com/moodle/moodle/commit/8c355f1f1c895739a4c404bcc2d500d166344bfc
+ 5.0 en [hidecategory,core]
+ 5.0 en [hidecategoryone,core]
+ 5.0 en [hidecategorymany,core]