UPDATE: code updated with new version of PARSE_INPUT and default values of CG fit adapted
to improved versino of OPTIMIZE_MINIMIZE.
Best CG fit is obtained using i) analytic evaluation of the gradient (i.e. for Delta fit mode), and
ii) keeping the tolerance around 1.d-5.

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.

small update: BHZ and BHZ-AFM updated drivers.
MICRO-BUG [fixed]: the newer version of OPTIMIZE_MINIMIZE with
shallow stop criteria for the CG fit revealed to be a bad one.
We updated the CGFIT routines by introducing a parameter *eps* that
was fixed before to eps=1.d-6, and use it to soften/harden the stop
criteria in the fit, together with tol parameter (which set how much
near zero the fit can reach).
This new parameter is useful in RDMFT, not that much in homo-ED.
The code has a new input variable: cg_eps, default is 1.d-6 to be
back-compatible with former results.

about changing cg_eps: this quantitiy "interpolates" between shallow and
picky stop criteria.
-cg_eps large [e.g. 1.d-2] does not allow for enough CG steps, reducing the
possibility of moving away from guessed point. This ends up *decreasing* DMFT
convergence rate.
-cg_eps small [e.g. 1.d-9] produces a very sensible CG fit with respect to the
input function (to be fitted), which can be problematic in some cases [e.g. inequivalent
sites].