Add new features to demo

[Tyriar]

We should add new features to the demo:

• fontSize
• fontFamily
• lineHeight
• themes

[theflyingape]

FWIIW, I am finding that the client WebSocket does not receive an onclose() event. The demo/app.js might need this event listener added in its app.ws():

  term.on('close', function() {
    ws.close();
  });

[Tyriar]

@theflyingape do you know if this would fix any bugs in the demo? Or is this just a general clean up thing?

[theflyingape]

Cleanup mainly. If you type exit in the shell it presents, the running backend app.js does not handle the PID closing, which in turn does not pass on the ws.on('close') event for its cleanup: echoing a 'Closed terminal ' + pid status. And a netstat confirms that the WebSocket remains ESTABLISHED between client/server without it.