Git commits in Moodle 2.1.1 by Andrew Robert Nicols

commit 757ca142ca9af7a75914eda31ce7061b70dc35ae
Author: Andrew Robert Nicols <andrew.nicols@luns.net.uk>
Date:   Tue, 05 Jul 2011 18:58:14 +0800
Tag:    v2.1.1

MDL-28193 Add $external arg to get_driver_instance