- dual functions in Delaunay class fixed (but code should still be improved)
- examples and demos modified accordingly
- broken: Hyperbolic_random_points_in_disc_2 and benchmarks (problems with number types)
basic fix of copyright headers
changed Triangulation_hyperbolic_traits into Hyperbolic_triangulation_traits
changed Delaunay_hyperbolic_triangulation into Hyperbolic_Delaunay_triangulation