Replaced python 2.x xrange to python 3.x range
use print instead of round
made functions more deterministic so probability doctests pass
fixed reference errors
fixed problems in data.doctest
fixed drt.doctest reference errors
added indents so comments aren't included in the doctest results
fixed unit test bugs for wsd
tokenize words in wsd.doctest
Merge pull request #673 from helmanofer/ofer_dev

Replaced python 2.x xrange to python 3.x range
Merge pull request #672 from jskda/pull_request.tests

Fixes to unit tests
whitespace normalisation
re-applied changes from https://github.com/nltk/nltk/commit/8dc5f5b5fda42ceff08ac7d3d47d1f795b30dfc3, cf https://github.com/nltk/nltk/issues/670
re-applied changes from https://github.com/nltk/nltk/commit/160a85d4551b3f629e725d1ee4a9f99666b75b45, cf https://github.com/nltk/nltk/issues/670
re-applied changes from https://github.com/jskda/nltk/commit/06d75ceaec1c561d5d5548b597db6e6bb26eb0a3, cf https://github.com/nltk/nltk/issues/670
re-applied changes from https://github.com/heatherleaf/nltk/commit/c65dffdf4bf10a81aa07e508175f7818a12f5183, cf https://github.com/nltk/nltk/issues/670