Move all (almost all) Go files in middleware into their
own packages. This makes for better naming and discoverability.
Lot of changes elsewhere to make this change.
The middleware.State was renamed to request.Request which is better,
but still does not cover all use-cases. It was also moved out middleware
because it is used by `dnsserver` as well.
A pkg/dnsutil packages was added for shared, handy, dns util functions.
All normalize functions are now put in normalize.go
Return a delegation when seeing one while traversing the tree in
search of an answer.
Put the SOA and NS record in the zone.Apex as these are to be handled
somewhat special.
Lowercase record on insert to make compares easier. This lowercases
all RR that have domain names in their rdata as well.
Drop the use of dns.RR when in fact the only thing we use is the name
and type of the RR. Cleans up a bunch of stuff and also stops the weird
making of dns.RRs just for a lookup. Should safe some memory as well.
Fixes: #66
When looking for a name in tree, return wether we got to a longer one -
if so we had an ent. Add tests + dnssec tests and refactor the tests as
well a bit.
