Git commits in Moodle 2.9.0 by Joshua Johnston

commit 7a6ca49af5ae52ca82f328b37a86822db5ee10ff
Author: Joshua Johnston <jojohnston@kaplan.edu>
Date:   Tue, 12 Aug 2014 05:16:30 +0800
Tag:    v2.9.0-beta

MDL-46651 Backup: Handle duplicate course completions during restore