Added shader fixes for Sky/stars/clouds for better sky mod compatibility and moved Dorkirt's mod to Optional Files

Do not use this fix if you can use HeliX mod d3d9.dll. Provided for DDD/iZ3D users who can't benefit from HeliX mod.

Use this mesh mod if you prefer Dorkirt\'s mesh fixes or if you can't use HeliX mod's d3d9.dll (DDD/iZ3D users).