decorator @py3_data for use with the file pointers in data.py
* for use on the initializers, e.g. BufferedGzipFile
* adds PY3/ to the data path for the following datasets:

  chunkers/maxent_ne_chunker
  help/tagsets
  taggers/maxent_treebank_pos_tagger
  tokenizers/punkt
apply @py3_data decorator to the path pointer init methods, to add PY3 to paths for selected corpora
Fixed doctests involving dict objects
Merge pull request #474 from wooters/master

Fixed doctests involving dict objects
merge framenet corpus reader from nschneid:patch-5, resolves https://github.com/nltk/nltk/pull/473
Merge pull request #470 from stevenbird/master

decorator @py3_data for use with the file pointers in data.py