Channels

Channels should be used to differentiate modules on the same domain. For example, a `chat` and a `game` channel could be separated as specified below:

``` js
import WsxClient from 'wsx/client';

const wsx = new WsxClient();

// Client#channel(name) should return a new Client instance
// which sends and parses messages on the given channel
const chat = wsx.channel('chat');
const game = wsx.channel('game');

// All of the events below are emitted separately
const noop = () => {};
chat.on('message', noop);
chat.on('join', noop);
game.on('join', noop); // Even this one
game.on('position', noop);
```

The syntax should be very similar on the server side.

Start with the Client#channel entry point named in the issue, then identify the corresponding server-side entry point. Verify that separate channel instances isolate message parsing and events, including events with the same name, and that the client and server APIs have matching channel behavior.

Written by the indexing model from the issue text.