CLT - results dictionary could be clearer

[joaopbernhardt]

In the results given by calc_stressCLT in the CLT module, the current returned data structure is like this:

return {"LCS" : {"strain" : {"inf" : LS_strain_inf,
                                 "sup" : LS_strain_sup}}, 
            "MCS" : {"stress" : {"inf" : MS_stress_inf,
                                 "sup" : MS_stress_sup}, 
                     "strain" : {"inf" : MS_strain_inf,
                                 "sup" : MS_strain_sup}}}

Where LS_strain_inf, LS_strain_sup... are lists of the size [3 x number_of_layers].
The dimension 3 is related to the 3 stresses/strains types (i.e. sigma1, sigma2, tau).
This means that the current format is:

MS_stress_inf = [sig_1, sig_2, tau]

It would be better to continue the formatting in a cascading dictionary for easier understanding of what the results hold, that is:

MS_stress_inf = {'sig_1': value, 'sig_2': value, 'tau': value}

This change will result in errors in the Failure Criteria module, which will have to be adjusted to this new format.

[joaopbernhardt]

Does this change has too big an impact in performance? I'll look into this.