Switch from histo to kde

Fixes #117 
Work in progress - uploading for review as I finalize this PR.

![screen shot 2014-12-19 at 9 55 16 am 2](https://cloud.githubusercontent.com/assets/1977405/5506156/610e6e68-8765-11e4-8a0d-0171c2fe0724.png)

Remove commented block