make nameserver information available on http server, add NameServerConfig

make nameserver information available on http server, add NameServerConfiguration
Please add JavaDoc to these. Also, what does `_ADDR` stand for here? The hostname? If so, please use `_HOSTNAME` as it is cleaner.

Also, should this really be bound by the user? The hostname and port of the name service is known to us, right? Or is this mean to be used internally?