Do not send in-band control traffic to the controller.

Do not send in-band control traffic to the controller.

This commit prevents the secure channel from sending any traffic to
or from the controller up to the controller over its OpenFlow connection.
Instead, such traffic is always handled completely locally.  This is
what the changes to in-band control up until now have been converging on:
each time, we have reduced the category of traffic that can be sent up
to the controller because we have found that doing so can cause a control
loop.  This change goes all the way.