Git commits in Moodle 3.1.6 by Skylar Kelty

commit 9c5c5e2ee673d22cff9dd47e35f58077d7a4bcb4
Author: Skylar Kelty <s.kelty@kent.ac.uk>
Date:   Thu, 13 Apr 2017 17:36:05 +0800
Tag:    v3.1.6

MDL-58590 mobile: Cache mobile-supporting plugins


commit 0f7ed737fca4d41464f135810b1106785a5e65af
Author: Skylar Kelty <S.Kelty@kent.ac.uk>
Date:   Thu, 06 Apr 2017 16:48:14 +0800
Tag:    v3.1.6

MDL-58456 chat: Add missing new in throw