add a __missing__ method so we don't have to hang on to a lambda, making ConditionalProbDist pickle-able
cleanup
make ConditionalProbDistI be a subclass of dict rather than defaultdict
add a test to show that ConditionalProbDist can be pickled
Merge pull request #394 from alexrudnick/pickle_ConditionalProbDist

Make ConditionalProbDist pickle-able by adding a __missing__ method
make nltk.tag.simplify_brown_tag not map -- to the empty string
Correct tnt.train() initialization (fix #398)
Merge pull request #400 from rmalouf/tnt

Correct tnt.train() initialization (fix #398)
Merge pull request #399 from alexrudnick/brown_simplify_handle_dashdash

make nltk.tag.simplify_brown_tag not map -- to the empty string
Make sure we close the file descriptor when writing to the megam training file.
Merge pull request #402 from alexrudnick/fix_megam_file_leak

fix file descriptor leak when writing to megam training file