Git commits in Moodle 3.3.1 by Andres Melo

commit f13c34e4a9ace16eb5dd1fbc8d014361b301d8f9
Author: Andres Melo <andres.torres@blackboard.com>
Date:   Thu, 18 May 2017 05:48:43 +0800
Tag:    v3.3.1

MDL-46322 mod_assign: Only list enrolled graders as potential markers