11-jun-2001 NvE ResultError correctly set in GetMomentum() of AliTrack and AliJet.

11-jun-2001 NvE ResultError correctly set in GetMomentum() of AliTrack and AliJet.
12-jun-2001 NvE Error calculation improved for spherical and cylindrical coord.
                in Ali3Vector::GetErrors().
13-jun-2001 NvE Memberfunctions GetVecTrans() and GetVecLong() introduced for
                Ali3Vector and Ali4Vector.
                Also GetScaTrans(), GetScaLong() and GetPseudoRapidity() introduced
                for Ali4Vector to provide a basis for e.g. E_trans and E_long calc.
                Memberfunctions GetPt(), GetPl(), GetEt(), GetEl() and GetMt()
                introduced for AliTrack and AliJet.
                For AliTrack there is an additional GetMt(j) to provide the Mt
                value for the jth mass hypothesis.