gluster: use remove brick cli xml output

glusterVolumeRemoveBrickStart, glusterVolumeRemoveBrickStop,
glusterVolumeRemoveBrickCommit and glusterVolumeRemoveBrickForce use
gluster cli xml output than stdout parsing.

glusterVolumeRemoveBrickStart is not consumed by engine/RHS-C yet,
its OK to differ in compatibility issue now.

Change-Id: I973b14fd94b1059540c38bb6e4590493075c45dd
Signed-off-by: Bala.FA <barumuga@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/13005
Reviewed-by: Timothy Asir <tjeyasin@redhat.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>