Gzdoom does not work

[Edward-san]

Hopefully fixed in this commit.
This doesn't happen to me on Windows with OpenGL 3.1 but now it should work everywhere.

Thanks, that worked.

[_mental_]

For some reason mipmaps are generated for font textures and value from gl_texture_filter CVAR is used to set filtering mode. In GZDoom 1.x it was always GL_LINEAR for font textures so text was always clearly visible.

[Graf Zahl]

Let me take care of those issues one at a time. I can't make all those changes simultaneously. Right now I am busy with the models, so that they get properly precached and interpolated on old hardware. Feel free to fix what you can quickly do.