[io vview] catch bad position/orientation values before error
[io vview] catch bad position/orientation values before error

Some recent simulations occasionally generate bad position data,
inf/nan, but it's nice to be able to see the results anyway.

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