[numerics] try to reorganize nsgs with sparse storage
[numerics] try to reorganize nsgs with sparse storage

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