Fixup: glewinfo on Mac needs to call RegalMakeCurrent with the appropriate context.
Fixup: Slence mac cglang build warning about unused parameter.
Use glGetProcAddressREGAL for GLEW_REGAL purposes.
GLEW_REGAL touch-ups for using glGetProcAddressREGAL.
Windows fixup for glGetProcAddressREGAL
For GLEW Bug #242 - glVertexArrayVertexAttribDivisorEXT missing