Git commits in Moodle 2.6.7 by David Monllao

commit c9fa67f7cba63fc1191eba691569b11dd6736430
Author: David Monllao <davidm@moodle.com>
Date:   Mon, 01 Dec 2014 10:29:05 +0800
Tag:    v2.6.7

MDL-48329 core_message: Checking that messaging system is enabled