In-page notifications

I think we need something like this to message the user - Eg, you've got a new notification, this happened, you favourited this thing...

API looks a bit like this,

```
var n = new Notify({ text: 'You got a new notification' }).tell();
```

![notify](https://cloud.githubusercontent.com/assets/84996/4664211/2d2c00e2-5542-11e4-82a5-6d916f9f6082.gif)