Author: Tim Hunt
MDL-67947 questions: questions_in_use should ask all components
Previously it was only checking mods.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=887daf932cac2554982f4dc9bcb49db2da9ded5a
http://github.com/moodle/moodle/commit/887daf932cac2554982f4dc9bcb49db2da9ded5a
+ 3.9 en [questionsinuse,core_question]