Add initial GL direct rendering test.
Fix viewport when rendering to FBO.
Add get_proc_address.

Render something "real" in GL.
Render something in motion.
Handle GL state more carefully.
Merge branch 'master' into gl-render
Fix some possible segfaults with HW render.
Test GL core works in GLES as well.
Fix Win32 HW render.
Add depth/stencil buffers to HW GL.
Merge branch 'master' into gl-render
Merge branch 'master' into gl-render
Clean out some more GL state.
Drop ALPHA_TEST. It is legacy GL.
Be more explicit about GLES2 or GL context.
Use VAOs for completion.
Mark SET_HW_RENDER as experimental more explicitly.
Merge pull request #169 from Themaister/gl-render

HW GL render for libretro.