-- v2: d3dx9: Add support for mipmap generation to D3DXCreateVolumeTextureFromFileInMemoryEx(). d3dx9: Use d3dx_image structure inside of D3DXCreateVolumeTextureFromFileInMemoryEx(). d3dx9: Cleanup texture value argument handling in D3DXCreateVolumeTextureFromFileInMemoryEx(). d3dx9: Refactor texture creation and cleanup in D3DXCreateVolumeTextureFromFileInMemoryEx(). d3dx9/tests: Add more tests for D3DXCreateVolumeTextureFromFileInMemoryEx(). d3dx9: Use shared code in D3DXLoadVolumeFromFileInMemory().