Git commits in Moodle 1.9.2 by danmarsden

commit eb6fad813f73282473b2ac2fe9cbc264ad06bcf7
Author: danmarsden <danmarsden>
Date:   Thu, 29 May 2008 10:02:39 +0800
Tag:    v1.9.2

MDL-14550 really inefficient db calls - saves almost 3x number of users in site for backup queries. merged from head.