Redefined PMAP_CONTRIB_SCDEFAULTS to conform to standard Shirley-Chiu parameters (normal, up vectors) used by rfluxmtx. For this we needed to reverse the corresponding vectors in ray2bin(), since the photon ray accepted by this function points away from its origin (= hitpoint). Also modified pmapcontrib.h to unconditionally enable PMAP_CONTRIB if PMAP_OOC is enabled.