Git commits in Moodle 3.6.x by Peter Spicer

commit 9eac8576498fd6c264ac92f1bf9f1b5b39e0b572
Author: Peter Spicer <peter.spicer@catalyst-eu.net>
Date:   Wed, 10 Oct 2018 17:29:15 +0800
Tag:    v3.6.0-beta

MDL-63451 core_message: Properly escape URLs for notification popup