update: small update in bhz_afm. introduced reduced sites symmetry to
speed and stabilize the code.

update: small improvements from devel_MPI and updated SciFor

update: added Broyden mixing in BHZ.
this is still under development, use with caution.
lines are commented, now.

update: BHZ-AFM driver updated with A(k,w) evaluation.

update: added analytic gradient for the chi^2 fit also in the
Superconducting channel for cg_scheme=delta. Test for Bethe lattice
successful.
BUG [SOLVED]: a micro-bug hidden in the arpack interface +lanczos_arpack.f90

setting info=0 and resid=0.d0 forced the toss of a random vector INSIDE the
arpack routine, using the LAPACK interface. This made the user lose contact
with the starting, random vector.
This caused serious problems in the RDMFT application and in parallel calculations,
where the random vector was most proabably slightly different from call to call, giving rise
to slightly different values in the eigen-vectors, ultimately leading to DIFFERENT impurity
Green's functions with the same input bath (!!)

FIXED: we generate an identical input vector resid from fortran random number generator (KISS)
using seed=1234567 (the good old hirsch-fye qmc). This ensures that all processed, threads or sites
have identical inputy vectors, notwithstanding their situation.