Fix: [Win32] now we are drawing on a tick, no longer use WM_PAINT

WM_PAINT hits when-ever Windows feels like, but always after we
marked the screen as dirty. In result, it was lagging behind,
giving a sub-60fps experience.

With the new draw-tick there is no longer a need to be driven by
WM_PAINT, so it is better anyway to drive the drawing ourself. As
an added bonus this makes the win32 driver more like the others.

src/video/win32_v.h

@@ -45,6 +45,9 @@ protected:
 	Dimension GetScreenSize() const override;
 
 	float GetDPIScale() override;
+
+private:
+	void CheckPaletteAnim();
 };
 
 /** The factory for Windows' video driver. */