[io] vview: use some numpy vectorize
[io] vview: use some numpy vectorize

     in those 2 functions:
     - set_dynamic_actors_visibility
     - set_position

     + split actors dict in dynamic_actors + static_actors

     Note: after looking again at some visualisations on chute con rocas
     there is no doubt that this is the multiple actors per object that
     does not scale (and finally this is obvious to me now).

radarsat1/siconos,bremond/siconos,fperignon/siconos,fperignon/siconos,siconos/siconos,siconos/siconos,siconos/siconos,bremond/siconos,siconos/siconos,radarsat1/siconos,radarsat1/siconos,fperignon/siconos,radarsat1/siconos,fperignon/siconos,fperignon/siconos,radarsat1/siconos,bremond/siconos,bremond/siconos,bremond/siconos