Git commits in Moodle 3.3.1 by Adrian Greeve

commit 7255306cc8c9aa9f0c76f8f3b70a288c0e68822f
Author: Adrian Greeve <adrian@moodle.com>
Date:   Mon, 12 Jun 2017 12:02:08 +0800
Tag:    v3.3.1

MDL-58729 database: Improve performance of CLI tool.