- Parse OpenGL version in sdl_glimp.c to share with both renderers.
- Add GL_VERSION_ATLEAST(major, minor) macro.
- Get address of glGetStringi if using OpenGL 3.
- Fix glConfig.extensions_string when using GL3 core context in
opengl2 renderer.
- Make opengl1 renderer's gfxinfo support qglGetStringi too.
Calling glClear( any bits ) in GL_SetDefaultState makes connect screen black using the proprietary NVidia driver on Windows and GNU/Linux.
This reverts commit 92573270de.