Starter code for 11-711 Homework #4.

To run:
python Parser.py train.conll development.conll > output.conll

The parser runs in unlabeled mode by default. To enable labels, use the -l flag.
With the given features, training your parser should take approximately one
minute unlabeled, or ~10m with labels.

Note that several functions have intentionally been left blank. It is your job to fill
in these functions to achieve a baseline parser. From there you should improve the learner,
the feature functions, or the parsing algorithm in order to achieve better UAS and/or LAS.