Game data for 3D Pinball Space Cadet must be placed in mass:/APPS/3DPINBALL

Changelog

• Backend: Replaced SDL audio and SDL mixer with PS2SDK's audsrv.
  • This decreased the ELF size to around 4.09 MB.
• Added splash screen with loading text
• If both games are on the USB, you can now pick whether to play 3D Pinball or Full Tilt Pinball
• Pinball game view is now centered on the screen instead of being fixed to the top left corner