Git commits in Moodle 2.8.9 by Mark Nielsen

commit 0c2ddb687ab976cacbf5952a44c82b45ec0ebd03
Author: Mark Nielsen <mark@moodlerooms.com>
Date:   Wed, 23 Sep 2015 03:04:28 +0800
Tag:    v2.8.9

MDL-51498 core_grades: Prevent unnecessary grade record fetching