-softblit uses SDL2 software renderer backend for blitting

SDL_UpdateTexture is apparently not good for streaming textures.
So instead, I did SDL_LockTexture/Unlock.

GL_EXT_texture_filter_anisotropic is cool I guess

GL Initialization needs to happen before window creation,
otherwise the GL library will get reloaded while in use and
Windows will have a heart attack. This is bad, obviously.

This is a massive performance boost on slow processors, because
before, the intermediary buffer had to be swizzled to ABGR8888
before being uploaded -- for large resolutions this was an
enormous performance penalty.

wolfs authored 10 years ago and Alam Ed Arias committed 10 years ago

Switch the Linux symbolic links with manual copy-pastes, should fix compiling on Windows for most users.

Also, fix the issue pointed out by Alam.