idl: use common netlogon bit definitions

idl: use common netlogon bit definitions

The DS_ bits had got a bit ahead of the NBT_ bits.

Ideally we'd make these a single set of bits at some point.

This also removes NBT_SERVER_DNS_FOREST as this bit doesn't exist. I
think it came from someone mis-reading the docs, which show the bits
in reverse order within bytes (one of the worst bit table
representations I have ever seen!)