Added stackedbars

Likely; I think I forgot to pull down the latest index.js so I was pushing the old one to the new one. Here is a video of me using the merge tool for the first time:
![craterface](https://cloud.githubusercontent.com/assets/7108211/3637582/63f64c5a-1013-11e4-892f-d73e823785e2.gif)

Do I need to do anything to fix?