[io] add opacity management to static objects and re-enable viewing of Volume and Shape Objects
[io] add opacity management to static objects and re-enable viewing of Volume and Shape Objects

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