Author: John Okely
MDL-56646 assign: Add ability to fix errant grades
http://git.moodle.org/gw?p=moodle.git;a=commit;h=76eefdded3995bb12e63b9ff66108e7c0f93fd22
http://github.com/moodle/moodle/commit/76eefdded3995bb12e63b9ff66108e7c0f93fd22
+ 3.3 en [fixrescalednullgrades,mod_assign]
+ 3.3 en [fixrescalednullgradesconfirm,mod_assign]
+ 3.3 en [fixrescalednullgradesdone,mod_assign]