Git commits in Moodle 3.5.2 by Henning Bostelmann

commit f5d6dcfd062cc1a52526956fbb6fd83f5becd9bf
Author: Henning Bostelmann <henning.bostelmann@york.ac.uk>
Date:   Sat, 14 Jul 2018 01:25:28 +0800
Tag:    v3.5.2

MDL-62914 Calendar: handle TZURL iCal property