Git commits in Moodle 2.5.6 by Henning Bostelmann

commit eed14281d468338ae85f58e868f41b06e31a0eb4
Author: Henning Bostelmann <henning.bostelmann@york.ac.uk>
Date:   Fri, 07 Mar 2014 22:57:24 +0800
Tag:    v2.5.6

MDL-44502 filelib: Add mimetype for Maple worksheets