added Atlas tool (which paint texture on the ground)
pencil is faster
pencil attenuation has three modes : rough, brush and noise
changed ground textures for testing purpose

added simple XML for future map serialisation
Worked on the map deserialisation : texture atlas ca be saved and restored.

Ground textures, normals and scales, plus cliff shapes are now defined as xml elements.
Warning, factory only instanciates the defaut StdMapStyle for now. do not change.

tangents and binormals are recalculated at realtime so normal mapping is always working.