Git commits in Moodle 2.5.3 by Jean-Michel Vedrine

commit 4f80368f824789286f5110b87a1cb4092c1bc869
Author: Jean-Michel Vedrine <vedrine@vedrine.org>
Date:   Thu, 31 Oct 2013 00:55:34 +0800
Tag:    v2.5.3

MDL-41624 DragMath crashes Firefox