Non-zero imaginary part in the latest release

[aeantipov]

anderson.pomerol --U 1 --beta 26 --levels -0.677193904997332 -1.63229282488024 0.677193904997332 1.63229282488024 --hoppings 0.155286870457831 0.312708587859944 0.155286870457831 0.312708587859944 --calc_gf 1 --calc_2pgf 1 --2pgf.indices 0 1 0 1 --2pgf.coeff_tol 1e-12 --2pgf.reduce_tol 1e-5 --wf_min -20 --wf_max 20

in cxx11 mode produces non-zero imag part.
This is not related to tolerances - single site has the same problem.

[aeantipov]

The issue is that the impurity is not half-filled. The right call is
anderson.pomerol --U 1 --ed -0.5 --beta 26 --levels -0.677193904997332 -1.63229282488024 0.677193904997332 1.63229282488024 --hoppings 0.155286870457831 0.312708587859944 0.155286870457831 0.312708587859944 --calc_gf 1 --calc_2pgf 1 --2pgf.indices 0 1 0 1 --2pgf.coeff_tol 1e-12 --2pgf.reduce_tol 1e-5 --wf_min -20 --wf_max 20