Git merges in Moodle 3.1.10 by Damyon Wiese

commit 28964ed251601777600a549a52952af535fe3a6f
Author: Damyon Wiese <damyon@moodle.com>
Date:   Mon, 11 Dec 2017 09:49:00 +0800
Tag:    v3.1.10

Merge branch 'MDL-61002-31' of git://github.com/andrewnicols/moodle into MOODLE_31_STABLE