not much happening here, just organizing thoughts
BaseDirect3DSurface for use with surface proxies
Direct3DSurface9Vireio proxy for stereo surface handling.
D3DProxyDeviceSimultaneous removed and code moved to D3DProxyDevice where it should be. (was separate to try and avoid breaking existing proxies but that  was just going to create a mess so dumped that idea.)
Initial basic render target duplication added.