Git commits in Moodle 2.8.8 by Nelson Moller

commit df0c2e957899654d744d7f41f5fea6b19c954c09
Author: Nelson Moller <nmoller@crosemont.qc.ca>
Date:   Fri, 14 Aug 2015 02:13:41 +0800
Tag:    v2.8.8

MDL-51090: mod_quiz grading validation of an essay question