Add native runtime mip map generation to Fast3D

[blackhand1001]

Image quality and texture aliasing would be significantly improved if we generated mipmaps and used them during rendering. It would allow proper anisotropic filtering to work as well.

Here is a comparison of what it looks like. Look at the grass in particular. I also included a screenshot from goldeneye.

I created these screenshots by forcing mipmaps and anisotropic filtering via the gpu driver into the old glide64 final plugin for comparisons sake. Unfortunately screenshots don't fully do it justice since the aliasing is most noticeable during motion.

Mipmaps

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Mipmaps

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