Git merges in Moodle 3.6.1 by Andrew Nicols

commit c69f425a7a6cf26148d4ac93570a037c32eb45e7
Author: Andrew Nicols <andrew@nicols.co.uk>
Date:   Mon, 03 Dec 2018 08:35:32 +0800
Tag:    v3.6.1

Merge branch 'MDL-64300_36' of git://github.com/stronk7/moodle into MOODLE_36_STABLE