Git commits in Moodle 2.8.6 by Dan Bennett

commit 116f2c571443d14c41c29dd1a2405a42fa1409cf
Author: Dan Bennett <dan@howtomoodle.com>
Date:   Tue, 10 Mar 2015 00:03:12 +0800
Tag:    v2.8.6

MDL-49104 repository_s3: backport of MDL-43725