Git commits in Moodle 2.4.2 by Michael Aherne

commit 53c07f1644511b9a6c151f1f5f413f04f0f77bb5
Author: Michael Aherne <michael.aherne@strath.ac.uk>
Date:   Fri, 11 Jan 2013 19:12:33 +0800
Tag:    v2.4.2

MDL-27164 groups Do not show multiple instances of the same role as multiple