Avoid passing this anywhere in the client code. It should only be set right before rendering the 3D view and the only code using the base palette should be the 3D renderer and hud_drawsprite.
Also make the palette override CVARs 3D view only in debug mode.
- delete some voxel code that's software rendering only.
- apply Big Endian byte swapping for SFXs, as well, now that this no longer involves hacking the file system cache.