use Eigen arrays and matrices instead of linalg.{h,c}pp classes

Note: still need to convert the indices at the vertices
run sums from 0 to N-1

This is the first step towards the index convention to C form.
However, the index literals like in ZE[gI1, 3] still need to be
converted to ZE[gI1, 2]
decrease integer literal indices on model input and output parameters

This replaces for example in the vertices

  ZP[gO1, 1] -> ZP[gO1, 0]
  ZP[gO1, 2] -> ZP[gO1, 1]

Still missing: self-energy expressions of the form

  -4*AbsSqr(CpconjVWmHpmAh(2,2))*B00(p,MAh(2),MHpm(2))

need to be replaced by

  -4*AbsSqr(CpconjVWmHpmAh(1,1))*B00(p,MAh(1),MHpm(1))
convert self-energies to C index convention
use C index convention in the convergence tester
use C index convention in the low-scale constraint
print non-perturbative value of sin(ThetaW)
set top and bottom quark index to 2 (C convention)
correctly return sqrt of array / vector
convert the particle indices in the scale definitions to C convention
generalize the DoubleVector <-> Eigen matrix conversion routines
make MSSM model test program compile
make the MSSM spectrum test compile
correct index access in MSSM model test
correct index access in MSSM low-scale constraint
Always convert indices at Delta(i,k)
convert tadpole equation indexing to C convention
convert neutralino / chargino self-energy indexing to C conversion
correct tadpole indexing in the susy-scale constraint
adapt MSSM mixing matrix tests to Eigen's output convention