GetWindow and SwapBuffers are function of Windows.h and using the same
name causes a compile error.
This commit also changes Util's GetProcTableAndDevice to CreateNXTDevice
because we might need to call NXT procs when creating the C++ device.
* First API design (many features missing, including input attachments)
* Metal implementation (no OpenGL yet)
* Render-to-texture demo (a little broken until we have depth buffers)
* Update examples to use render passes
Kai Ninomiya
Corentin Wallez
Austin Eng