Git commits in Moodle 2.6.x by Chris Wharton

commit a423acd95c3b51197fd95f7feaa5b77264712a65
Author: Chris Wharton <chrisw@catalyst.net.nz>
Date:   Thu, 18 Jul 2013 09:44:26 +0800
Tag:    v2.6.0-beta

MDL-40700 cache: Validate memcache key prefix field