Simple handle estimator

Estimate "Handle" for segmented point clouds based on cylinder assumption.
This is a super-early version.

![screenshot_from_2014-06-25 19 31 29](https://cloud.githubusercontent.com/assets/40454/3384095/008a3c80-fc54-11e3-8802-f0488817af2e.png)
![screenshot_from_2014-06-25 19 32 14](https://cloud.githubusercontent.com/assets/40454/3384096/008a4f0e-fc54-11e3-8918-0866bf25a87b.png)