Computational changes / interall classifier added

Reworked computations for speed up purposes
* Python 'dict's replaced by sortable tuples
* Parallelization expanded
* Binary search through words to find frequencies faster

Internal classifier added
* Classifier takes Naive Bayes probabilities and predicts confidence intervals
* Holdout data produced from training data to train the classifier
Internal classifier not json writable
Utils expanded
Unit tests added for utils
Renamed to crossvalidation.py
Main file: extracts features and runs CV