Git commits in Moodle 3.4.0 by Andres

commit 373d7d3f282f9e421256f8a0ce21173a9df3a7ac
Author: Andres <andres.torres@blackboard.com>
Date:   Fri, 19 May 2017 10:58:24 +0800
Tag:    v3.4.0-beta

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