Git commits in Moodle 2.4.6 by Nitzan Bar

commit 1fdb431dfef333332ffc5d9178f21cfb17089b67
Author: Nitzan Bar <nitzanbar@macam.ac.il>
Date:   Thu, 15 Aug 2013 21:27:01 +0800
Tag:    v2.4.6

MDL-41259 when duplicate course shortname exists an exception is thrown and sync is aborted