Fix hyperparams bugs in base and random. Fix extracted forest size used in random. Factorize random fitting

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

Speedup similarity forest regressor and add parallelization at the extracted forest size level in the training

Fix parallelization and estimator default hyperparams in kmeans and similarity methods. Fix on resume mode in train.py. Fix stage5 saving (tmp) in compute_results.py

Add on resume mode for the experiment training (and set the overwrite of the resulting model of the experiment optional)

Add Paolo's first implementation of this paper: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2822360/

- Add new results for stage4.