[dns-operations] Short NS record names

[Simon Munton]

dot-PL (NASK) do it slightly differently, may be to avoid the 
"delegation-only" issue Joe describes.

a-dns.pl. c-dns.pl. d-dns.pl.e-dns.pl. f-dns.pl. g-dns.pl. h-dns.pl. 
i-dns.pl.

Matt's comments RE: signing obviously still apply.

>  1. There is no need to look up any delegated zone (e.g. nic.hu) when
>     resolving ns1.nic.hu.

Our experience is that resolvers rarely do this with TLDs, but rely on 
the A & AAAA records in the ROOT zone - but our tests in that area were 
primarily done before DNSSEC, so may no longer apply.