Implemented display ColorPicker in a simple Activity

Hi Sir,

I just implemented to show ColorPicker in a simple Activity to the current library. Hope it'll save some body's time like me. Thank you for your excellency and generosity to share this code. Complete credits goes to you. I've done nothing major in it. Just added changes to get my requirement and thought it would help to somebody like me as i didn't able to find any web reference to implement a ColorPicker in a simple Activity. So, shown a little courage to contribute to your sourcecode.

Hope It makes sense. Attached screen shots.
![2014-04-09-12-48-55](https://cloud.githubusercontent.com/assets/592596/2652827/18f32bac-bfb8-11e3-928e-040417a03f46.png)
![2014-04-09-12-49-11](https://cloud.githubusercontent.com/assets/592596/2652828/1921f52c-bfb8-11e3-9d1b-7f02b289957b.png)
![2014-04-09-12-49-24](https://cloud.githubusercontent.com/assets/592596/2652829/19507e56-bfb8-11e3-9abd-566a323ea01d.png)

Thank you again,
PraveenB (Y)