We acknowledge the Geneva group for comments on their evolutionary tracks.
The work was partially supported by the INTAS grant No 93-3364, grant of Russian Fund for Basic Research No 95-02-06053a, grant JAP-100 from the International Science Foundation and Russian Government and by Center for Cosmoparticle Physics ``COSMION'' (Moscow, Russia). The work of S.N.N., I.E.P. and S.B.P. was supported by ISSEP.