Author: Tim Hunt
MDL-31080 quiz editing, must be able to see and delete missing questions
http://git.moodle.org/gw?p=moodle.git;a=commit;h=ce7595e6df508a6543f548437365abe9635036b3
http://github.com/moodle/moodle/commit/ce7595e6df508a6543f548437365abe9635036b3
+ 2.1 en [missingquestion,mod_quiz]