Git commits in Moodle 2.6.2 by James Pratt

commit b98bc5cb98c6ad89c30fc96a122519c3a07506d2
Author: James Pratt <me@jamiep.org>
Date:   Fri, 13 Dec 2013 16:51:07 +0800
Tag:    v2.6.2

MDL-43369 : quiz statistics - average across attempts where item seen