better handling of opened files (msh+pos)
min/max computation for msh pos

There was a mistake in the GUI, the options in a view were always applied to view 0, have fixed the bug -jf

Better visualization if isosurfaces, with the same
light model on both faces. I'm gonna do something better
in the near future.

I hope cvs is enough clever to ged rid of ^M
genereated in windows, let's pray ...