Author: Tim Hunt
MDL-74610 quiz: multiple grades - reset all button
http://git.moodle.org/gw?p=moodle.git;a=commit;h=9a1b85aa4cd23bd0f7ffe8711a6fda65020be444
http://github.com/moodle/moodle/commit/9a1b85aa4cd23bd0f7ffe8711a6fda65020be444
+ 4.4 en [gradeitemsremoveall,mod_quiz]
+ 4.4 en [gradeitemsremoveallconfirm,mod_quiz]
+ 4.4 en [gradeitemsremoveallmessage,mod_quiz]