Forward port PDQ 3489: turn off cont & act updates

This is a simple sub-classing of the proper update methods to
just no-op their behavior.

Change-Id: Ib1ae5234d372cbce572da34cfe702235b78f2310
Signed-off-by: Peter Portante <peter.portante@redhat.com>
Reviewed-on: http://review.gluster.org/5088
Reviewed-by: Luis Pabon <lpabon@redhat.com>
Tested-by: Luis Pabon <lpabon@redhat.com>