Merge fixes and improvements from NOLF2-modernizer

[a-hurst]

Not sure if you've seen it, but there's a project similar to this one (but with a much more limited scope) where an enthusiast has taken the 32-bit Windows-only NOLF2 source and made various changes to add quality-of-life features and fix bugs on newer systems: https://github.com/haekb/nolf2-modernizer

That project's not touching the Lithtech engine itself at all, but they do have some preliminary work done in another repo on an OpenGL renderer based off of the debug symbols in the OS X binary of the game, which might be useful: https://github.com/haekb/OpenRen

[Katana-Steel]

Looks nice, good to have multiple project with different goals.
My main focus isn't really NOLF2 but FEAR, I know it doesn't show yet.
My primary goal isn't just to get an OpenGL or Vulkan renderer, but a workable
Linux version of the LithTech engine

[rohit-n]

Some improvements have been pulled from the modernizer. See the following merged PRs.

#46
#55