Git commits in Moodle 2.3.8 by Andrew Davis

commit 6250057612791aa6b4bcb169aeab940c48421644
Author: Andrew Davis <andrew@moodle.com>
Date:   Fri, 26 Apr 2013 10:37:52 +0800
Tag:    v2.3.8

MDL-35859 core_grade:fixed an optional parameter call to use the array version

commit f2f5e4dd448cfa9aebdf5dfd5d1b6e1da780520f
Author: Andrew Davis <andrew@moodle.com>
Date:   Mon, 28 Jan 2013 12:03:59 +0800
Tag:    v2.3.8

MDL-36090 core_grade: added logging of overriding of student grades