feat(router): improve log output.

Add information about the matched host (user application or deis component) and information about the router node.
There are a couple components that follow this same practice (though in practice `go-dockerclient` and `go-etcd`'s interfaces are much more stable):

https://github.com/deis/deis/blob/master/publisher/Dockerfile
https://github.com/deis/deis/blob/master/logspout/Dockerfile

:trollface: