Simple rename of Caddy/CoreDNS and some smallish cleanups.

See #1

Rename to test and name the toplevel tests dir to test for consitency.

Add a fullblown testing server. This allows us to do integration tests.

Also add a basic proxy test. Further tests will test etcd proxy
and stub zone communication and other "wildish" configurations.
Redo the server startup, so we can access the ports it listens on when
it has started up (with dns.ActivateAndServer).

Extend the .travis file to download etcd and test for that as well.

Put integration tests in test dir

This does not fix the reload issue, but will give us flexibility
to access the packetConn and listener to make this all work.

Tests updated as well and all the middleware. And Prometheus renamed to
metrics (directive is still prometheus).

Split up the previous changes a bit. This PR only returns the expected
error when the received packet has the wrong EDNS version.

EDNS0 handling in the middleware needs a nicer abstraction, like
ReflectEdns() or something.

Add port number to health check. Add tests the rewrite

middleware.



Fixes #36

We should not check the port of the request, we *should* actually
normalize it to port 53 - as that will probably be the address of
the server. Still need to double check if this will work if the
axfr should actually be done from a different port. That will come
later, this is good enough for now.

More tests and add RemoteAddr to State, prolly LocalAddr will be

useful as well.

Fixed and tested IsNotify method.

Test shouldTransfer by upping a testserver and sending the SOA query.

Remove state from DefaultErrorHandler and just get it from the request.

Add more logging to show what is going on.



This also adds the infrastructure for future tests.

If monitoring is enabled for one zone, also enable it for when the

server reports REFUSED. Normally the metrics are only enabled if

you enter the middleware, with this you'll see REFUSED queries.

Each of these are reported agains the root zone otherwise

Start http handler on port 8080 and return OK. Also add some

documentation fixes for the prometheus middleware.

For prometheus use the plain value, not a pointer and change all usages.
Allow AXFR to be requested over udp as well and some other more log
printed when commencing an AXFR.

Respond to notifies and allow a secondary to follow the SOA parameters

to update a zone from a primary. Also sprinkle it with logging.



Also extend monitoring to include qtype in more metrics.

Put some more logging in CoreDNS.

Remove placeholder for the docs inside the logs middleware and
explain response codes better.

Make the CH middleware actually work. Needs a bit of a hack to route

the fake version.bind and friends zone to the correct handler. Fiddle

with the order in directive.go so that CH queries get logged as well.



Secondly add class rewriting to the rewrite middleware handler and also

log the class by default.

Cache the size and the do bit whenever someone asked for it. We can

probably add more:



PASS

BenchmarkStateDo-4  	100000000	        11.9 ns/op

BenchmarkStateSize-4	 5000000	       265 ns/op

ok  	github.com/miekg/coredns/middleware	2.828s



PASS

BenchmarkStateDo-4  	1000000000	         2.86 ns/op

BenchmarkStateSize-4	500000000	         3.10 ns/op

ok  	github.com/miekg/coredns/middleware	5.032s



This PR also includes some testing cleanups as well.

Rename latency to duration.

Fix some file/secondary issues when parsing a Corefile, also allow

for multiple origins to be specified. Also don't fail on startup when

a zonetransfer fails.



Fixes: #54

Allow specifying a primary server and retrieve the zone's content.

Add tests and an Expired bool to zone struct, to stop server zones

that are expired. The zone is retrieved on Startup, no updates of

changed content are done. We also don't respond to notifies yet.