Git commits in Moodle 2.6.3 by Henning Bostelmann

commit 4b05939d2f1e62f36e080c277129c57957d2e30a
Author: Henning Bostelmann <henning.bostelmann@york.ac.uk>
Date:   Fri, 07 Mar 2014 22:57:24 +0800
Tag:    v2.6.3

MDL-44502 filelib: Add mimetype for Maple worksheets