Fixing mult_div_vector_t for the case where the sparsity of the (output) produc>
Fixing mult_div_vector_t for the case where the sparsity of the (output) produc>

Also cleaning up a bit, and removing two unnecessary if statements.

jjo31/ATHAM-Fluidity,jrper/fluidity,jrper/fluidity,iakovos-panourgias/fluidity,rjferrier/fluidity,jjo31/ATHAM-Fluidity,rjferrier/fluidity,jrper/fluidity,iakovos-panourgias/fluidity,jjo31/ATHAM-Fluidity,jjo31/ATHAM-Fluidity,jrper/fluidity,iakovos-panourgias/fluidity,iakovos-panourgias/fluidity,jjo31/ATHAM-Fluidity,jrper/fluidity,rjferrier/fluidity,iakovos-panourgias/fluidity,rjferrier/fluidity,rjferrier/fluidity