dig/host/whatever assumes that it is using BIND8 code. mixing BIND4 in
libc with BIND8 code will result in very strange behavior, or program panics.
it is not necessary for dig/host/whatever to obey /etc/nsswitch.conf, actually
dig(1) is explicit about it.
now dist/bind is almost clean BIND822p5, with the following exception:
- /etc/irs.conf will never be visited when running BIND8 toolchain,
to make it less complex. the search order for BIND8 toolchain is
defined in dist/bind/lib/irs/gen.c:default_map_rules().
and usr.sbin/bind compiles them in BSD make framework, with no tricks at all.
