Author: Tim Hunt
MDL-42125 quiz stats: clearer message when manual grading required
http://git.moodle.org/gw?p=moodle.git;a=commit;h=9e5e0d8de438fd95b4068f569257addbf2e7ec11
http://github.com/moodle/moodle/commit/9e5e0d8de438fd95b4068f569257addbf2e7ec11
+ 3.2 en [nogradedattempts,quiz_statistics]