DatePicker center and fill width on iPad

On iPad the DatePicker was placed to the left side of the screen. This way it's centered and filling the entire width of the frame it's in. Also, you should probably make the sample an Universal App


![ios simulator screen shot 8 nov 2014 11 01 16](https://cloud.githubusercontent.com/assets/4228546/4963797/9bb545d4-672e-11e4-833d-d67e3633685d.png)
![ios simulator screen shot 8 nov 2014 11 02 25](https://cloud.githubusercontent.com/assets/4228546/4963798/9bbbf8b6-672e-11e4-87ad-53a17cb5c308.png)