Acknowledgments

This work has been supported in part by the Bulgarian National Foundation for Scientific Research under project $\Phi$-809, by the Polish Committee for Scientific Research (KBN) under Contract No. 5 P03B 014 21, by the Foundation for Polish Science (FNP), by the U.S. Department of Energy under Contract Nos. DE-FG02-96ER40963 (University of Tennessee), and DE-AC05-00OR22725 with UT-Battelle, LLC (Oak Ridge National Laboratory), by the US National Science Foundation under grant Nos. PHY-9970749 and PHY-0140036, and by the computational grants from the Regionales Hochschulrechenzentrum Kaiserslautern (RHRK), Germany, and from the Interdisciplinary Centre for Mathematical and Computational Modeling (ICM) of the Warsaw University.