Git commits in Moodle 2.5.0 by Tim Gus

commit e1580085c437445822061a795b1b3a1559a6774c
Author: Tim Gus <tim.gusak@remote-learner.net>
Date:   Sat, 05 Jan 2013 01:29:14 +0800
Tag:    v2.5.0-beta

MDL-31557 Add index for timemodified in grade_grades_history table