[cmake] Use ccache if available.
[cmake] Use ccache if available.

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