Git commits in Moodle 2.5.4 by rwijaya

commit 3a0be85aebd395c0c6d62b1e77407ff13b66600d
Author: rwijaya <rwijaya@moodle.com>
Date:   Tue, 10 Dec 2013 15:48:48 +0800
Tag:    v2.5.4

MDL-42104: trap tab focus within dialog modal,