Add more functionality to nanonameserver.

Add more functionality to nanonameserver.

- When no port is specified, pick the same port for UDP and TCP, so that
TCP fallback can be tested.

- Change handlers to get a single Request object instead of individual
parameters.  The Request object contains the message, peer, and
connection_type previously passed, and also adds the local address and
wire format message.  Additionally, it provides convenient properties
for accessing the question.