Local variable shadowing in global const. Now subsystem is back to
'dns'.

Add prometheus metrics to the cache handler. This just used prometheus,
if the metrics middleware does not setup the handler, there is nobody
reading these metrics, but they are still reported. Seems the simplest
solution while keeping the whole middleware separation in tact.

Also fix failing test in setup/error.

Put error back in the correct place in the directives.go. Also don't
make it a pointer. If it *is* a pointer the buildstack function does
not correctly set the Next Handler. Don't understand *why* this is
different from Caddy. Anyway this fixes it, with the caveat that
the error log file is now openend earlier in the startup.

Fixes #127

The endpoint for etcd as wrongly set if a proxy was configured.
Clean up some documentation in the process as well.

* Add middleware/cache

Add a caching middleware that caches nxdomain, nodata and successful
responses. It differentiates between DNSSEC on normal DNS replies.

Each reply is compress and scrubbed so it will fit the specific client
asking for it.

* first simple test, less exporting of stuff

* more

* Add middleware/cache

Add a caching middleware that caches nxdomain, nodata and successful
responses. It differentiates between DNSSEC on normal DNS replies.

Each reply is compressed and scrubbed so it will fit the specific client
asking for it. The TTL is decremented with the time spend in the cache.
There is syntax that allows you to cap the TTL for all records, no
matter what. This allows for a shortlived cache, just to absorb query
peaks.

+Tests

* cache test infrastructure

* Testing

A target of a cname must be put in the answer section. Fix this and add
a AAAA test for quad-AAAA CNAME responses.

Fixes #125

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.

Instead of watching a single file watch the entire directory and
catch the .Name from the event. On any event, just reload the damn
thing. This also fixes the problem of loosing events when the inode
changes.

Zone reloading

No reason why not to allow more then one address:
`transfer to 127.0.0.1 10.240.20.1`.

Fix startup as well, as it turned out to be broken...

Error out when parsing and transferring such a zone. If we would serve
it we would give out the wrong answers, leading to (probably) validation
failures...

Fixes #114

Fixes #109

Liberal as it as it still has its use. Reject invalid domain names
in the config.

Unrelated: clear up the README as well. And fix travis script.

Add some docker bits and a Makefile.

Use sync.Once to only transfer a zone once.

Fixes #115

The error propagation from srv.ListenAndServe did not work as intended,
simplified it a bit and added a test for it.

Copy and port the NS record stuff from SkyDNS. Slightly cleaner
implementation.

* Finish the nodata stuff. See issue #9
* middleware/etc: add response to SOA queries
* Remove and add a few TODOs

For the match function use the proper thing from go dns. Fix all
callers and tests to use this.

Fixes: #107

Test the handling of EDNS0 payloads and forwarding to stubzones
servers.

We don't need to network to do tests, we up enough local servers
to we don't need to forward to,s say 8.8.8.8

Simple rename of Caddy/CoreDNS and some smallish cleanups.

See #1