Allow connecting to devices via device name

[BrianGenisio]

This is mostly for convenience, but also for use in a lab setting where the devices are already provisioned and named. In our case, the chips will have the names on a sticker, so doing something like this would be nice:

var board = new five.Board({
  io: new Particle({
    token: 'MY_TOKEN',
    deviceName: 'downton_abbey' 
  })
});

At connection time, we'd query the devices on the given API token, find the device by name, and get the ID that way.

Thoughts? Objections? I'll probably pair that with a PR for allowing direct connections when you know the IP address: #67

[rwaldron]

Seems like a fine idea—as long as the current behaviour is unchanged.

[BrianGenisio]

Of course.