This version of the code gives same (==exact numbers) results
of the devel version at some commitment point before the introduction
of PARSE_INPUT and changes in file reading.

Code entirely written.
First debug successfull and tested against Massimo Capone lanczos code (MClanc).
Results at first DMFT loop for U=0 and U=1 give very same spectrum.
Green's functions are found in very good agreement and even better
fullfillment of the symmetry (i.e. Re_G or Re_Sigma identically zero).

Initial results for fully converged DMFT calculation obtained for U=2.
Order parameter is found to be on top of MClanc code.

To be fixed:
- Code to be cleaned.
- Delta functions routines in ED_BATH to be replaced with a unique subroutine
for real or matsubara frequencies.
- not interacting Grenn's function (impG0 and impF0) of the Anderson problem looks wrong.
Inversion to be check out.

Test against F. Petocchi results for bethe lattice in order.

Check signs on the real time green functions.
Signs are (hopefully) in agreement with my own calculations.
Symmetries of the GF seem to be correct;
there is still some mismatch in the comparison with adriano branch (devel)

Exept for these small bugs now I'm ready to code the real_space_dmft_ed
driver.

!+- NOTE -+!
This branch is just for testing...
It will be removed later
!+--------+!