WGL_ARB_pbuffer
http://oss.sgi.com/projects/ogl-sample/registry/ARB/wgl_pbuffer.txt
	WGL_DRAW_TO_PBUFFER_ARB 0x202D
	WGL_MAX_PBUFFER_PIXELS_ARB 0x202E
	WGL_MAX_PBUFFER_WIDTH_ARB 0x202F
	WGL_MAX_PBUFFER_HEIGHT_ARB 0x2030
	WGL_PBUFFER_LARGEST_ARB 0x2033
	WGL_PBUFFER_WIDTH_ARB 0x2034
	WGL_PBUFFER_HEIGHT_ARB 0x2035
	WGL_PBUFFER_LOST_ARB 0x2036
	HPBUFFERARB wglCreatePbufferARB (HDC hDC, int iPixelFormat, int iWidth, int iHeight, const int* piAttribList)
	BOOL wglDestroyPbufferARB (HPBUFFERARB hPbuffer)
	HDC wglGetPbufferDCARB (HPBUFFERARB hPbuffer)
	BOOL wglQueryPbufferARB (HPBUFFERARB hPbuffer, int iAttribute, int* piValue)
	int wglReleasePbufferDCARB (HPBUFFERARB hPbuffer, HDC hDC)
	DECLARE_HANDLE(HPBUFFERARB);