Git commits in Moodle 2.5.7 by James Pratt

commit 60c66becbcaa5db9637a07d79d1614aef2f2cab7
Author: James Pratt <me@jamiep.org>
Date:   Thu, 22 May 2014 13:10:07 +0800
Tag:    v2.5.7

MDL-42526 mod_assignment : fix record insert with assigment.id 0