DSTwo: Add a .gitignore entry.
OpenDingux: A big menu commit. Contains a menu system, GUI input repetition, as well as menu items for performance counters and ROM information, changing the video scaling, booting from the BIOS or the cartridge, showing or hiding the FPS counter, resetting the game and exiting. Nothing is saved to a file yet. The defaults are also full-screen with hidden FPS.

Button mappings have changed! X and Y are no longer rapid-fire buttons; Y now launches the menu (because Start+Select was sending the first button to the game); X+Y is no longer an exit hotkey, now that the menu system is starting out.

GCW Zero: Analog Up and Analog Down are no longer mapped to the screen scaling. Analog Right stays mapped to fast-forwarding.

Dingoo A320: Y+Select to change the screen scaling is now a superset of the menu hotkey, so it is changed to L+Select and R+Select.
OpenDingux: Using uint_fast8_t caps the FPS at 255, so use uint32_t instead.