just Polyhedron_3 with its potential template template parameter.
- Different names for the two versions: print_polyhedron_OFF and
print_polyhedron_header_OFF
- Added const declarations in test_polyhedron_io[_old].C to
the char * string constants.
- Updated demos to new kernel traits.
- Added std:: scope to less functor in triangulation_print_OFF.h.
- Added CGAL::to_double calls to point coordinates output.