Author: Jake Dallimore
MDL-67585 core_course: add favouriting to the content item service class
http://git.moodle.org/gw?p=moodle.git;a=commit;h=f09e9b887e92a868a6cfd6414314c65a8c84a6d4
http://github.com/moodle/moodle/commit/f09e9b887e92a868a6cfd6414314c65a8c84a6d4
+ 3.9 en [cachedef_user_favourite_course_content_items,core_cache]