Git commits in Moodle 2.8.x by Brian King

commit 6a97697a2af06690981845506d4a8009b0bc8426
Author: Brian King <brian@liip.ch>
Date:   Fri, 28 Jun 2013 17:10:16 +0800
Tag:    v2.8.0-beta

MDL-40371 Upgrade-until-22: remove obsolete _upgrade_grades functions