Also switch the localhost rule there, finishing migration
of all special names from the policy module.

fixes modules/dns64 test

Picked up old work, rebase-squashed after many months;
then fixed up a little as needed in this newer version.
(and later many minor fixes got squashed in)

See NEWS for 4.0.0: "always send DO+CD flags upstream".

We already had rank stored in there, in particular
entry2answer() always stored it.

- kr_layer_t isn't really useful in the inner functions
  (it's mainly useful through ->state when returning from layer)
- kr_query seems a little more suitable to pass than kr_request

manager: datamodel improvements

See merge request !1313