Git commits in Moodle 3.6.6 by Adrian Greeve

commit b6f9a29a5e2bec14dcb314b7d5b53e7cdf2eb03d
Author: Adrian Greeve <abgreeve@gmail.com>
Date:   Fri, 23 Aug 2019 12:55:26 +0800
Tag:    v3.6.6

weekly release 3.6.5+