Author: Marina Glancy
MDL-50586 gradingform_rubric: warn about missing 0-points levels
http://git.moodle.org/gw?p=moodle.git;a=commit;h=de9cd39715c4acf8ae74f11573aa538492d12c42
http://github.com/moodle/moodle/commit/de9cd39715c4acf8ae74f11573aa538492d12c42
+ 3.0 en [err_novariations,gradingform_rubric]
+ 3.0 en [zerolevelsabsent,gradingform_rubric]