PlayStation Mobile input fixes

Here are some simple fixes for input on PlayStation Mobile:

IsButton(Up|Down) weren't working for some of the thumbstick enumerations, so I implemented them.

The Y axis of the analog sticks was inverted, so I compensated for that.

In a recent SDK update they silently broke it such that the input APIs (for getting gamepad state, etc) will crash with a cryptic exception. I added code to detect this and rethrow it wrapped with a meaningful message so that the developer will know how to fix it.