Git commits in Moodle 3.0.4 by Henning Bostelmann

commit 16067645b40c3b19ff325323a34ace01e4579159
Author: Henning Bostelmann <henning.bostelmann@york.ac.uk>
Date:   Tue, 12 Apr 2016 02:45:26 +0800
Tag:    v3.0.4

MDL-53780 mod_assign: Remove teachers from submission group members