Author: Andrew Davis
MDL-46600 core_grades: made it explicit in the error message that a failed grade import means nothing was imported.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=5bfbec5521845bb1c29abc22fbd6f7432f8ff36b
http://github.com/moodle/moodle/commit/5bfbec5521845bb1c29abc22fbd6f7432f8ff36b
+ 2.7 en [importfailed,core_grades]