Developer credits
Git commits in Moodle 2.5.3 by Francis Devine
commit 85251082bf373249eba3792653fee793e6146f07 Author: Francis Devine <francis@xeon.pw> Date: Wed, 04 Sep 2013 17:21:41 +0800 Tag: v2.5.3 MDL-41417 course: prevent duplicate idnumbers being used when updating a course