Add NamedPipe transport

[worldbeater]

This allows using named pipes for a lightweight inter-process communication.

Server:

var router = new DefaultTargetSelector();
router.Register<IService, Service>();
var host = new NamedPipeHost(new Engine().CreateRequestHandler(router));
host.StartListening("AwesomePipeName");

Client:

var transport = new NamedPipeClientTransport("AwesomePipeName");
var proxy = new Engine().CreateProxy<IService>(transport);