Git merges in Moodle 2.9.9 by Andrew Nicols

commit 8c504c1f0e519464bf2119e83e8d4c60395b1bb8
Author: Andrew Nicols <andrew@nicols.co.uk>
Date:   Fri, 11 Nov 2016 15:14:36 +0800
Tag:    v2.9.9

Merge branch 'MDL-55121-29' of git://github.com/lameze/moodle into MOODLE_29_STABLE