Git commits in Moodle 2.7.5 by Dave Cooper

commit 0256434964cea10733cb755be35a04b56ce835dc
Author: Dave Cooper <dave@moodle.com>
Date:   Mon, 19 Jan 2015 13:16:48 +0800
Tag:    v2.7.5

MDL-48776 core_message: Fixed userid check.