[contrasting] add default pval equal to zero in gnFit (to avoid the program to crash when called by python). refactor anderson test. add anderson test by default for the one fold analysis.

[contrasting] harmonize gumbel altitudinal models. create plot_total_aic.py. remove exception for model with infinite aic.

[contrasting] add quadratic & cross terms Gumbel altitudinal models & fix a recurrent bug that happenning when checking the AIC value

[contrasting] add Gumbel altitudinal models. But so far only the first three models are passing tests (models with quadratic & cross terms are crashing)

This includes models that combine some quadratic aspect & a cross term.
Remove random test

the selection for the model with minimal aic only takes into account models with with finite aic (there are often several models with infinite aic)