GCW Zero: Add two empty header files for compilation to complete.
Merge https://github.com/pcercuei/ReGBA
Merge https://github.com/pcercuei/ReGBA
Merge https://github.com/pcercuei/ReGBA
GCW Zero: Compile with -mno-abicalls -mno-shared to avoid using global relocations and register $28.
Merge https://github.com/pcercuei/ReGBA
GCW Zero: -mno-shared is not actually needed. Add the new name of the executable to .gitignore.
GCW Zero: Render to the right surface, using the right color format.

video.h: Define the color format used by the GBA as GBA_{RED | GREEN | BLUE}_MASK.
GCW Zero: Fix bad centering of the screen.
GCW Zero: Add unremappable input so games can be controlled. Rapid-fire A and B are Y and X respectively.
GCW Zero: Shorten the input button update function, as suggested by JohnnyonFlame.
Typos are my bane.
video.h: The order is actually BGR 555. Modify this in documentation. Thanks Paul Cercueil.
GCW Zero: Use a 240x160 render surface for the GBA game. This avoids blitting the black border constantly with color conversion (38400 pixels per frame).
GCW Zero: Updated scaler by Paul Cercueil.
GCW0: OPK: Open with a GBA ROM or ZIP file.
GCW0: Added .gitignore to hide OPK files