use topo render, volume explode render and clipping plane
	can load .tet or use cubes

Pickable: add constructor that generate LineDrawable for you
FrameManipulator: small bug in scale
shaderExplodeVolumes invert clipping plane direction

modification topoRender for using dartIndex

-> use map.dartIndex(d) instead of d.index
add new orbits (orbit_in_parent), functional with Map & GMap
-> storage of attributes not operational with EmbeddedGMaps
add traversor for incident cell of volume

add middle dart position computing

a define in tuto*.h allow testing with gmap

small modif for warning in image class of MC
removing of unused code (testing) in map2