Implement modes 3 and 4
Implement modes 3 and 4

Anty-Lemon/mgba,nattthebear/mgba,Touched/mgba,iracigt/mgba,fr500/mgba,sergiobenrocha2/mgba,Touched/mgba,sergiobenrocha2/mgba,Iniquitatis/mgba,Iniquitatis/mgba,fr500/mgba,MerryMage/mgba,zerofalcon/mgba,bentley/mgba,mgba-emu/mgba,Anty-Lemon/mgba,Iniquitatis/mgba,libretro/mgba,cassos/mgba,askotx/mgba,sergiobenrocha2/mgba,MerryMage/mgba,libretro/mgba,mgba-emu/mgba,bentley/mgba,AdmiralCurtiss/mgba,askotx/mgba,cassos/mgba,nattthebear/mgba,libretro/mgba,jeremyherbert/mgba,fr500/mgba,Anty-Lemon/mgba,Iniquitatis/mgba,sergiobenrocha2/mgba,sergiobenrocha2/mgba,mgba-emu/mgba,libretro/mgba,Anty-Lemon/mgba,zerofalcon/mgba,matthewbauer/mgba,fr500/mgba,iracigt/mgba,libretro/mgba,matthewbauer/mgba,iracigt/mgba,AdmiralCurtiss/mgba,jeremyherbert/mgba,cassos/mgba,Touched/mgba,jeremyherbert/mgba,AdmiralCurtiss/mgba,zerofalcon/mgba,iracigt/mgba,mgba-emu/mgba,askotx/mgba,MerryMage/mgba,jeremyherbert/mgba,askotx/mgba