Git commits in Moodle 2.5.2 by Chris Wharton

commit fe6eeced0b2775863fb197d2d5d112580bed4757
Author: Chris Wharton <chrisw@catalyst.net.nz>
Date:   Thu, 18 Jul 2013 09:44:26 +0800
Tag:    v2.5.2

MDL-40700 cache: Validate memcache key prefix field