Show example with other transports

[jbenet]

Would be nice to show an example using other transports (utp, udt, once they works...) to show off that ma-pipe can be used to connect transports of different sorts. (more powerful nc)

particularly powerful with proxy:

> ma-pipe proxy /ip4/127.0.0.1/tcp/0
listening on /ip4/127.0.0.1/tcp/65053

# elsewhere
> connect to /ip4/127.0.0.1/tcp/65053
/ip4/1.2.3.4/udp/1234/udt
<reliable-transport>