Modified tagger.py. Now includes function to train Brill tagger (pretty much useless), and a function tag tokens that couldn't be tagged by first tagger (backoff tagger) using WordNet. Wordnet tagger works well, but this commit only implements a first pass using WordNet. Only tags tokens that have an exact match in WordNet, and whose synsets POS tags don't include 'v' (verb) and only have one tag --'n' (noun), 'r' (adverb) or 'a' and/or 's' (adjectives/adj_satellites)--.