Implement SDL3 for the SDL port if the CMake definition ENABLE_SDL3 is
set.
Implement setting the color depth for both wxWidgets and the SDL port.
Fix the coloring issues in the SDL port for OpenGL.
Implement 8 bit color support.
Update and fix the wx port SDL sound driver.
Implement SDL video in the wx port.
Silence GL deprecations on macOS.
Add SDL renderer selection.
Fix filter for bit depths other than 32 bit.
Fix GDK backend for Linux.
Add Metal renderer for macOS.
Fix Quartz drawing.
