train classifier script with options
corpus reader creation, instance extraction, feat & eval options
can train & evaluate bayes and megam binary classifier on movie_reviews
word scoring, pickle dumping
initial nltk_training.classification modules working
multi binary reuters classification works
move train_classifier to top level so no PYTHONPATH needed

--HG--
rename : scripts/train_classifier.py => train_classifier.py
initial readme
test different colons in readme
doc updates
fixups
initial non-working train_tagger.py
train_tagger works with builtin corpora, including switchboard
can train classifier tagger on switchboard discourses
corpus reader for timit tagged sentences
can train a brill tagger with variable symmetric template bounds
sequential backoff algorithms with multiple affix taggers
confirmed to work on floresta, cess_esp
cleanup, tagger pickling
better help formatting, readme updates