Git merges in Moodle 2.7.15 by Eloy Lafuente (stronk7)

commit 5b25976c77dda2d16eb39aa9be0f862505d22a4a
Author: Eloy Lafuente (stronk7) <stronk7@moodle.org>
Date:   Sun, 10 Jul 2016 06:28:59 +0800
Tag:    v2.7.15

Merge branch 'install_27_STABLE' of https://git.in.moodle.com/amosbot/moodle-install into MOODLE_27_STABLE