We are grateful to ACK CYFRONET - Krakow for the computer time. Dr. K. Boryczko's and Mr. R. Wcislo's help in final preparation of the manuscript is kindly acknowledged.
The work has been partially sponsored by Polish State Committee for Scientific Research (KBN) Grant No. 8 T11F 003 12. J.K. is grateful to AGH Grants 11.120.16 and 11.120.420 for support.