Git commits in Moodle 2.9.1 by Skylar Kelty

commit 69afba56e69d4eff7abe81f5f7a2b21d676ba207
Author: Skylar Kelty <S.Kelty@kent.ac.uk>
Date:   Mon, 18 May 2015 23:47:25 +0800
Tag:    v2.9.1

MDL-50280 WebCT import scripts don't always clean up

commit 35a0d150313cd95af71226f0ac18a040237f0acb
Author: Skylar Kelty <S.Kelty@kent.ac.uk>
Date:   Tue, 12 May 2015 15:03:56 +0800
Tag:    v2.9.1

MDL-50169: Fix grade report SQL logic