Git commits in Moodle 2.1.5 by Michael Aherne

commit e0325d3c30d7d558219d729947d66a4eec1c5f36
Author: Michael Aherne <michael.aherne@strath.ac.uk>
Date:   Wed, 08 Feb 2012 22:41:38 +0800
Tag:    v2.1.5

MDL-31495 Performance improvement in question engine upgrade SQL