Git commits in Moodle 2.7.2 by John Okely

commit 5f399d0c526d62529a0cc9bbf99b4996de0b71b6
Author: John Okely <john@moodle.com>
Date:   Thu, 17 Jul 2014 16:42:42 +0800
Tag:    v2.7.2

MDL-45339 Libraries: Add a note to docblock of get_config, set_config, and unset_config to note they are used in lib/db/upgrade.php