#119 Ability to change Menu button on joypads on Raspberry Pi

[windale]

Hi, can we have a way to map the Menu button to a different joypad button on the Raspberry Pi version please ? At the moment it's hardcoded to Joypad Button 0 which is the main firebutton on a lot of Joypads and there's no way to get rid of it or map it to a different button.