Git commits in Moodle 3.1.0 by Henning Bostelmann

commit 64ccb37d499ad3d5918120db7a8cd47164526afc
Author: Henning Bostelmann <henning.bostelmann@york.ac.uk>
Date:   Tue, 12 Apr 2016 02:45:26 +0800
Tag:    v3.1.0-beta

MDL-53780 mod_assign: Remove teachers from submission group members

commit 3847c105b00ca716b6bb80bd859cb684a0a7a620
Author: Henning Bostelmann <henning.bostelmann@york.ac.uk>
Date:   Tue, 10 Nov 2015 07:22:53 +0800
Tag:    v3.1.0-beta

MDL-52086 output renderers: show subtree only when tab is activated