asMatrixCsrListw: Convert spatial weights list to CSR matrix form
Description
asMatrixCsrListw creates a matrix.csr from a listw object, asMatrixCsrIrW is a helper function used in fitting SAR models and elsewhere to make a (I - rho W) matrix.csr object from W; asListwMatrixCsr performs the reverse conversion from matrix.csr to listw object.