Git commits in Moodle 3.5.3 by Mark Nelson

commit bb34fe0838a1aa60810820cfadbbb2644ef3d02c
Author: Mark Nelson <markn@moodle.com>
Date:   Mon, 05 Nov 2018 10:35:51 +0800
Tag:    v3.5.3

MDL-63839 core_message: use component name for Behat tag

commit ff5ec88a55731222b952cdd537747b8f11271d10
Author: Mark Nelson <markn@moodle.com>
Date:   Tue, 11 Sep 2018 12:57:30 +0800
Tag:    v3.5.3

MDL-63333 core: removed unused setting 'messaginghidereadnotifications'

commit af142c1c2dfb6d80c6d5fcd09f21a01ac635aff1
Author: Mark Nelson <markn@moodle.com>
Date:   Thu, 06 Sep 2018 18:12:21 +0800
Tag:    v3.5.3

MDL-63130 core_message: add unit test