Mouse Joystick autoswitch option

Amiberry uses a feature coming from WinUAE, which helps have multiple controllers and a mouse connected at the same time, but switch between them on-demand.

The option "Mouse/Joystick autoswitching" (found in the Input Panel) works as follows when enabled:

• Short press on a controller button, or move RIGHT, will place it in Port 2 (joystick port)
• Long press on a controller button, or move LEFT, will place it in Port 1 (mouse port)