MAINTAINERS: Adding new sub maintainers.

http://supercolony.gluster.org/pipermail/gluster-devel/2014-December/043177.html


Change-Id: Iec587f383cf8da9832932194e2518a6bd99c6380
Signed-off-by: Humble Devassy Chirammal <hchiramm@redhat.com>
Reviewed-on: http://review.gluster.org/9266
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Reviewed-by: Shyamsundar Ranganathan <srangana@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>