We can't completely avoid it, since gl's headers use these defines for
their header guards, and we really do need to stop the system GL
headers from doing anything.
Fixes#14
For performance, I want to be able to make single-context (well,
single-pixel-format-and-device) apps be able to directly call GL
functions through function pointers. Bake that into the ABI now so I
can get a release out the door and fix this up later.
This also fixes the lack of __stdcall annotation on the
PFNWHATEVERPROC typedefs.
This lets the compiler generate faster function calls (call through
function pointer, instead of call into a linker-generated stub func
containing jump to function pointer).
I was thinking at one point that part of the build was going to
require not including the #defines from the generated code, but would
want these prototypes. It turns out that's not the case (and if it
is, I'll just wrap the #defines in an ifdef).