Improved tilt control

This was more of a "for fun" thing than anything else.

Now, you can use tilt controls to control the analog stick, D-Pad as well as the PSP action buttons. Cleaned up the code a bit too. 

Screenie:
![screenshot_2013-10-27-23-34-05](https://f.cloud.github.com/assets/1694861/1429276/b903563a-40b0-11e3-9b2e-31097b5e543c.png)