It was impossible to perform an energy scan in EIG spectroscopy.
The calculator and calcio modules were corrected.
We can now compute the spectral radius vs energy with and without
renormalization for EIG spectroscopy mode
The G_n, Sigma_n, Z_n and Lowdin K^2 methods are supported for
the inversion algorithm.
This commit fixes also several issues in the GUI and in the
hemispherical_cluster function