v1.3.0

All changes in this release were provided by contributors!

• Many SDL2 improvements and corrections @vanfanel
• Overlay support rewrite @vanfanel
• Threading improvements @vanfanel
• Fixed aspect ratio when starting in fullscreen @vanfanel
• Added scoreboard overlay for Dragon's Lair @vanfanel
• Improved overlay transparency @lmerckx
• Option to disable SDL hardware acceleration @DavidGriffith
• updated SDL2 keycodes @OzFalcon
• usb scoreboard interface @mcspaeth