`TfpgGDIWindow`
pt		DoAllocateWindowHandle
pt		DoReleaseWindowHandle
pt		DoRemoveWindowLookup
pt		DoSetWindowVisible
pt		HandleIsValid
pt		DoUpdateWindowPosition
pt		DoMoveWindow
pt		DoWindowToScreen
pt		DoSetWindowTitle
pt		DoSetMouseCursor
pt		DoDNDEnabled
pt		DoAcceptDrops
pt		DoDragStartDetected
pt		GetWindowState
		Create
		Destroy
		ActivateWindow
		CaptureMouse
		ReleaseMouse
		SetFullscreen
		BringToFront