Rewrite scripts in C/C++ and export data to XML and Collada

[JayFoxRox]

When unpacking binary data, they should be converted to XML, to make it easy to modify them. This is already done for the model files by Sw_Racer.

Doing this for the texture, spline, sprite and savedata files would allow users to modify and repack these files more easily.

Data which is not easily modifieable by text editors, should be extractable to PNG (as it already happens for sprite and textures) or Collada from the XML.