If there's an error binding to the socket (not sure what kind of error would happen, but I imagine there might be some case), how does node deal with that? In general, I'm not totally clear on how we should be dealing with errors in Node code (as opposed to Connect code, which seems to consistently pass errors down through the middleware)--are exceptions thrown, is there an error event, etc.? The Node docs aren't entirely clear on this point. (`http.Server` has a `clientError` event, but that doesn't sound like an event that would be thrown if `server.listen()` fails, for example.)