Git commits in Moodle 2.9.1 by Marc Català

commit d68806edf96e8c2ad223421747ddc08912a738d8
Author: Marc Català <reskit@gmail.com>
Date:   Sat, 20 Jun 2015 19:02:22 +0800
Tag:    v2.9.1

MDL-50652 workshop: Workshop module allows duplicated ID number