Feature/bubblechart

![bubblechart](https://cloud.githubusercontent.com/assets/539905/5207940/2cf69366-757d-11e4-854f-7d723ca54190.png)

Also, if we are going to be doing quite a few string formatting operations, consider implementing a method with a signature similar to this:
```
MOS.Util.strFormat(formatStr, params);
// Example usage
var translateStr = MOS.Util.strFormat('translate({x}, 0)', {x: this.options.margin});
// Output: 'translate(25, 0)'
```