[numerics] avoid assert, nu use numerics warning when tolerance vanishes
[numerics] avoid assert, nu use numerics warning when tolerance vanishes

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