Git commits in Moodle 2.5.x by Nitzan Bar

commit 9dccff7793524e3503e7f520b2a91143a6d973f0
Author: Nitzan Bar <nitzanbar@macam.ac.il>
Date:   Thu, 15 Aug 2013 21:27:01 +0800
Tag:    v2.5.2

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