util: added FileUtils containing method that returns a list of file names given a directory
added test method that takes a list of sentences and returns a tuple containing LAS, UAS, speed in tokens/sec, speed in sentences/sec; added command line options for specifying a directory from which to read train/test/dev files
modification to increase speed (via Alex): if we see a token-tag pair 1000 times in training, consider that a sure thing and don't try to learn it; modified accuracy method to return a tuple containing token accuracy, sentence accuracy, speed in tokens/sec, total number of tokens processed; added test method that takes a list of sentences and basically formats the result of calling accuracy on it; added command line parameters to specify a directory from which to read train/test files
make sure to freeze features after deserializing; added test method that takes a list of Documents and returns a tuple containing speed in sentences/sec, speed in tokens/sec, and F1