Add Support for D3DFMT_X8R8G8B8 (#214)

This would "fix" the exported xml from having "22" in the embedded texture's format block.
In before this 22 prevents the xml file from importing into blender via Sollumz, caused the common error "KeyError:22" when some people editing weird-making mods.

CodeWalker.Core/GameFiles/Resources/Texture.cs

@@ -659,6 +659,7 @@ namespace CodeWalker.GameFiles
     public enum TextureFormat : uint
     {
         D3DFMT_A8R8G8B8 = 21,
+        D3DFMT_X8R8G8B8 = 22,
         D3DFMT_A1R5G5B5 = 25,
         D3DFMT_A8 = 28,
         D3DFMT_A8B8G8R8 = 32,