* Make CoreDNS a server type plugin for Caddy
Remove code we don't need and port all middleware over. Fix all tests
and rework the documentation.
Also make `go generate` build a caddy binary which we then copy into
our directory. This means `go build`-builds remain working as-is.
And new etc instances in each etcd test for better isolation.
Fix more tests and rework test.Server with the newer support Caddy offers.
Fix Makefile to support new mode of operation.
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.
