added some instructions for nmssm model files in sarah.
Needs work and flexibleSUSY parts to be added.
added instructions to create Z3NMSSM directory from SARAH directory.
Mild change to eralier part to avoid name clashes with existing directories.
src/linalg2.hpp: add procedures following SARAH conventions

The mixing matrix conventions for (symmetric) svd are from
Haber and Kane, Phys. Rept. 117 (1985) 75-263.
I could not find where the sfermion mixing convention is originally from.
src/linalg2.hpp: add a real -> complex svd procedure

From: Alexander Voigt <Alexander.Voigt@physik.tu-dresden.de>
Subject: Re: BPMZ convention in diagonalize_symmetric
To: Jae-hyeon Park <jae-hyeon.park@tu-dresden.de>
Date: Mon, 11 Nov 2013 10:10:53 +0100

One remark: In my current development branch I have the following
extra routine which I need to handle real mass matrices in combination
with complex mixing matrices:

// m == u.transpose() * s.matrix().asDiagonal() * v
// (convention of Haber and Kane, Phys. Rept. 117 (1985) 75-263)
// (s >= 0).all()
// s in ascending order
template<int M, int N>
void sarah_svd
(const Eigen::Matrix<double, M, N>& m,
 Eigen::Array<double, MIN_(M, N), 1>& s,
 Eigen::Matrix<std::complex<double>, M, M>& u,
 Eigen::Matrix<std::complex<double>, N, N>& v)
{
    const Eigen::Matrix<std::complex<double>, M, N>
        m_complex(m.template cast<std::complex<double> >());
    sarah_svd(m_complex, s, u, v);
}

Could you please consider adding a routine (or similar) with this signature?

Many thanks,
Alex
Merge branch 'master' of ssh://pktlogin.phy.tu-dresden.de/soft/users/theory/FlexibleSUSY
Merge branch 'master' into eigen-matrices
adapt diagonalization function calls to the new naming scheme
relax test precision to make the {N,S}MSSM tests pass

There seems to be a numerical difference in the output of the dia-
gonalization routines between Softsusy and Eigen of the order
1.0e-11 ... 1.0e-12