Git commits in Moodle 2.4.x by Francis Devine

commit 5f8e23c1a92f37fba3d33553bd2dc351e1eb8685
Author: Francis Devine <francis@xeon.pw>
Date:   Wed, 04 Sep 2013 17:21:41 +0800
Tag:    v2.4.7

MDL-41417 course: prevent duplicate idnumbers being used when updating a course