Git commits in Moodle 3.2.x by Brendan Anderson

commit c28c76450b40e5cf5c39aa97b1f0fbafb565e136
Author: Brendan Anderson <brendan_anderson@hcpss.org>
Date:   Tue, 25 Oct 2016 03:22:13 +0800
Tag:    v3.2.0-beta

MDL-54112 mod_assign: Add scale null grade filter