Git commits in Moodle 2.8.12 by David Monllao

commit 28908d2d6a10aee451033f05bff34dfbcdb8aaa9
Author: David Monllao <davidm@moodle.com>
Date:   Mon, 02 May 2016 16:37:29 +0800
Tag:    v2.8.12

MDL-54008 tz: Avoid using Caracas tz