Adding button/axis definitions for PS3 controller.

Adding PS3 button and axis definitions. Also threw in a minor fix to Input.hx. I was getting the following error when compiling for Flash:

com/haxepunk/utils/Input.hx:290: characters 79-80 : Cannot skip non-nullable argument useCapture

so I added in an explicit "false" for useCapture, and the problem was solved.