Git commits in Moodle 2.1.3 by sam marshall

commit d33c06621a61a3f63e3a92e50f545adb05e9de9a
Author: sam marshall <s.marshall@open.ac.uk>
Date:   Tue, 11 Oct 2011 00:25:06 +0800
Tag:    v2.1.3

MDL-29501 Gradebook should not show links to activities that aren't available to user