add icann.dns to meta-TLD

added icann.dns support to the http server
returns dns response json
> Problem is, while we can copy the resultant packet from the request in oldDNSLookup (and replace this line)

So do it. :+1: (Unless there's a reason not to...?)

> there are no packets to copy from in resolve; it creates a new packet where there was only a 'path' string before.

Did you have a look at [this giant comment above `callback:`](https://github.com/okTurtles/dnschain/blob/86a340119ca912f17147365f7be40147d7c8527b/src/lib/dns.coffee#L63-L103)?

It explains the way `native-dns` works, and where to look for classes and whatnot. But I'm pretty sure you know that since you wrote: 

```coffeescript
# fields from: https://github.com/tjfontaine/native-dns-packet
```

So then you should know that you can simply:

```coffeescript
req = new require('native-dns-packet')()
```

(Except I wouldn't do it with an inline `require` like that.)