Git merges in Moodle 3.1.12 by David Monllao

commit 7c362df750940fef7bbf372723b474b48efa20c0
Author: David Monllao <davidm@moodle.com>
Date:   Tue, 15 May 2018 15:42:18 +0800
Tag:    v3.1.12

Merge branch 'install_31_STABLE' of https://git.in.moodle.com/amosbot/moodle-install into MOODLE_31_STABLE