Add FunKey S / Q36 Mini / RG Nano build

Added support for "Sonic 3D Blast 5"

Added savestate autoload/autosave feature

Same changes as previous commit, part 2.

Fixed A/B buttons being inverted in the "Alternate 2" button layout".

Added support for new beta opendingux

- Added support for new beta opendingux
- Updated GBC mime types
- Preliminary work for supporting OGA screen resolution (maybe in the
future)

Fixed framedrop in the menu entry animation when entering the menu wh…

…ile in ffwd mode.

Multiple changes.

- Changed name to Gambatte-DMS (dot matrix simulator) to avoid confusion
with other outdated forks
- Added an extra button layout option (alternate 2) to mirror
Select/Start buttons into X/Y
- Added option to disable the Fast-Forward hotkey
- Preliminary work on a future scaler for devices with VGA screens
- Added support for low battery warnings on miyoo consoles (not used in
normal builds)
- Preliminary work for a future auto-shutdown feature (shuts down when
battery level is too low) on miyoo consoles

Various changes

- Fixed OPK desktop settings
- Cleaned up menu keybind related code to better support the
bittboy/pocketgo versions
- Changed version label to r572u4
- Updated manual and readme

Added an option to select the system priority when a ROM supports bot…

…h DMG and GBC modes.