Redoing baselines

See merge request !192

Created a getter and a setter for the BioAlgorithmLegacy.base_dir and fixed an issue during the scoring

Implementation of S-norm

See merge request !190

Segmenting the scores and biometric references checkpoints by group to avoid too many files in one directory

Score normalizations

See merge request !188

Remove vstack_features -> use the one in bob.pipelines

See merge request !187

Wrappers and aggregators

See merge request !185