Git commits in Moodle 3.5.1 by Ed Basset

commit a31a20a5c6aaee150a5a3ca67a315f5217c02fb7
Author: Ed Basset <ed.a.bassett@gmail.com>
Date:   Mon, 21 May 2018 18:15:26 +0800
Tag:    v3.5.1

MDL-36424 wiki: set group so subwiki tabs/pages display correctly