[swig] Do not assume (in)SiconosMatrix& is not SP
[swig] Do not assume (in)SiconosMatrix& is not SP

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