BIND-free mode

All of our users at the outset, and maybe for a while, will be using Stork Kea and not for BIND. Can we make it a configurable setting whether you are using Stork with BIND or Kea, and hide the BIND dashboard or menu choices, links to the BIND docs, etc, if the admin is not using it with BIND?

At one point when I suggested this, Godfryd said that this might be something Stork could just infer from the servers it was configure to monitor - that is fine too, and I suppose even cooler, but either is ok.

There are several places in the UI where we mention BIND, perhaps we can remove those as well for the time being.