Git commits in Moodle 2.9.3 by Mark Nielsen

commit 3876164bb98d937c40ad89048bddd1651f0c3b4f
Author: Mark Nielsen <mark@moodlerooms.com>
Date:   Wed, 23 Sep 2015 03:04:28 +0800
Tag:    v2.9.3

MDL-51498 core_grades: Prevent unnecessary grade record fetching