Git commits in Moodle 2.6.6 by Jon Marthaler

commit 80c90ea46b41cc3551c37ed065ed2b85b1abc3e2
Author: Jon Marthaler <jmarthaler@gmail.com>
Date:   Fri, 17 Oct 2014 11:24:27 +0800
Tag:    v2.6.6

MDL-38065 gradebook: Fix issue with hidden categories breaking rowspan.