Git commits in Moodle 2.5.6 by Jonathon Fowler

commit 0859a464cb1a64a745e1b8ec82aec01dbf3a2107
Author: Jonathon Fowler <fowlerj@usq.edu.au>
Date:   Tue, 15 Apr 2014 12:18:55 +0800
Tag:    v2.5.6

MDL-44270 files: handle drag-drop js error when event has null types