refactored MLE class in order to support WCE, standard embeddings and combinations;
sketched out NN implementation for WE compositionality;
still TODO SIF embeddings;
new op.arg -t ['MUSE', 'FastText']
uploaded /results/results.csv (on rcv1 ... run0.pickle) obtained on all available setup.
TODO: refactor it also as a standalone class with its own load/weighted sum/extract/reduce methods.