All typedefs for structs that were present in other header
files have been moved to here. (Except node_t because the
renderer and netcode both define node_t LOL.)
A flattened-commit port of the SRB2 repository's software-slope-plane-uv-fix-attempt/merge request 1464 due to the vast, vast refactorings that would intefere with brightmaps and Encore if done one commit at a time.
Object tracking is off, but it was off before so I don't know if I actually
broke it. Minor refactoring in HWR_RenderPlayerView and HWR_RenderSkyboxView.
The skybox rendering process has been replaced with portals instead. Those are generated after the first BSP tree pass by looking for existing sky visplanes at the time, and their windows are used to define new portals.
The skybox portals are still incomplete and cause visual glitches when masked elements are involved.
Split portal-related code to its own source files.
Most of the 2-line-specific setup has been moved to the function which adds a 2-line case. The portals should render as they used to so far, anyway.
* Palette remaps.
* Branding.
TODO:
* Doesn't work in GL. (Mostly.) I have SOME ideas on how to tackle this, but...
* Transmaps are broken in Encore for some reason.
* I tried to make in-level colormaps shimmy over, but it didn't quite work, so I commented it out and only semi-fixed it.
* Remove FUNCMATH from all void-returning functions, given GCC80 specifically complains about this case.
* Extend the length of all extant buffers to the safety threshold recommended by the compiler.
* Add void casts to WS_getaddrinfo's setting to prevent complaints about incompatible typecasts.
* Extend the charsel, face, and superface buffer sizes and writes to include the null terminator. (I didn't really want to do this because it's not even particularily NEEDED, but there was literally zero way to get around the request that I could find with multiple online searches. I tried.)
