Allow using DX9Ex in DirectX renderer

This commit enables DirectX 9EX feature inside DX9 renderer for T3D.
I already saw that there was code for support, so this commit only enables feature what is already present inside T3D, but for some unknown reason to me it was never enabled or used.

see http://msdn.microsoft.com/en-us/library/windows/desktop/ee890072(v=vs.85).aspx for further details.