Git commits in Moodle 3.1.5 by sam marshall

commit 691868bdaa8bc1659e13080accae74f08b8982bd
Author: sam marshall <s.marshall@open.ac.uk>
Date:   Mon, 09 Jan 2017 22:24:11 +0800
Tag:    v3.1.5

MDL-57601 Grade report: Error for ungraded quiz without view hidden


commit bc1643135cdf8ba6845f3ee6a1068fee395f1e29
Author: sam marshall <s.marshall@open.ac.uk>
Date:   Thu, 22 Dec 2016 23:31:25 +0800
Tag:    v3.1.5

MDL-57515 Resource: 'not very efficient' with a large number of files