bugs in ED_GETH fixed.
Some of the multi-orbital terms in the hamiltonian were wrong.
The diagonal part was accumulated after the spin-flip and pair-exchange parts, which would
have led to an error.
Better handling of the hfmode and density-density terms.
Merge branch 'devel_multi-orbital_nomix' into devel

Conflicts:
	ED_GETH.f90
Merge devel_multi-orbital_nomix with devel branch.
Conflicts resolved.
Minor bugs caused by conflict resolution fixed.
Lanczos evaluation of the GS updated with Nblock bug fixed, from mpi_parallel branch.
Code tested for 2band HM on Bethe with same U different Eloc.
Very same results found from the two branches.
>>> DEVEL_MULTI-ORBITAL_NOMIX BRANCH IS DELETED <<<
update: added complex lanczos routines from test directory.
update: small bug fixed in GETGF, not deallocating bosonic freq.
update: the MPI_ version of the code has been added to the actual devel_ code and commented, so to unify the
future developments.

complex lanczos routines added from testing directory. ready to extend the code to complex case (spin-orbit coupling).
update: note that this version has not been thoroughly tested, so be careful.

code updated with newer version of the (complex) sparse_eigenspace, sparse_matrices
developed in the testing directories.
Re-factory of the code with unification of the lanc/full ed algorithm.
The ED code now provides a single interface, in DMFT_ED, that can be
used in f2py-->python.
Main modules have been renamed using more evocative names.

fix: control variables for the Lanczos procedure have been rename.
lanc_nblock has been deleted as it is easily fixed by lanc_neigen.
The lanczos condition is now ARBITRARILY set to dim<10, for which
full diagonalization is performed instead of lanczos.

The code is ready to be extended to finite T and complex case.