Fix flw_pairs loading. Prepare all new exps: omp_distillation, preds coherence, preds correlation, normalize_D when OMP, n_jobs=-1 in SOTA. In exps script, test both train+dev,train+dev and train,dev

Update fix of normalize_D in the case of wo weights. Add density plot in compute results for all stages and add some plots in results.

Integrate Paolo's code of method 'Ensemble selection from libraries of models' by Rich Caruana et al

- Add stage4 (results and experiments);
- Do not save model object.

- Add diamonds in experiment scripts and add factorize run_compute_results.sh script;
- Add best params for diamonds dataset.

- Remove extracted_forest_sizes_number parameter from compute_results.py and retreive the value instead;
- Add almost all remaining experiment config files of stages 1, 2 and 3;
- Add almost all remaining result plots of stages 1, 2 and 3;
- Add some temporary scripts to run all stages experiments.