add cloth classification sample

This nodelet will classify the softness as below.

![originalpicture](https://cloud.githubusercontent.com/assets/3803922/3183176/1e9c8c78-ec64-11e3-8ebf-4c5f80fcf40a.png)

random points will show as below result
![goodpicture](https://cloud.githubusercontent.com/assets/3803922/3183179/2ea99318-ec64-11e3-838f-04191dc33d16.png)

segmented will show as below result
![segmented_result](https://cloud.githubusercontent.com/assets/3803922/3183182/3b6d65b6-ec64-11e3-8876-8b18ce38c9de.png)