Git commits in Moodle 3.1.9 by David Monllao

commit 0b4293759988b35210501ebdff78d0818fa6a0cc
Author: David Monllao <davidm@moodle.com>
Date:   Fri, 27 Oct 2017 18:48:23 +0800
Tag:    v3.1.9

weekly release 3.1.8+