Explicitly mention setuptools 0.6 in install.rst

Setuptools merged with Distribute in 0.7. I think setup.py needs to be migrated to 0.7?
Merge pull request #1 from nltk/master

Updating
Merge pull request #429 from jskda/master

nltk fixes
Merge pull request #430 from jskda/master

PY3 fixed xml decoding detection bug
PY3: fix nltk.classify.tadm
rename compat._im_class to compat.get_im_class because it is not private
Lowest Common Hypernyms Change & Tests

- Set lowest_common_hypernyms to use max_depth by default
- Updated wup_similarity() to use min_depth with LCH
- Added a tests file for wordnet (only tests lowest_common_hypernyms()
at the moment)
- Added an additional LCH example to demo() which illustrates a case
where a target synset is also the LCH for itself and another synset
doctest and docstring updates
improve word_tokenize speed

Runs roughly twice as fast on my test set of 40000 sentences. According
to kernprof (http://pythonhosted.org/line_profiler/), the culprits of the
previously bad performance were

    r"([^' ])('ll|'re|'ve|n't|) "

and

    r"([^' ])('LL|'RE|'VE|N'T|) "

which were matching all words due to the | at the end.

Also removed some useless whitespace handling that was being undone by the
str.split just before return.

The contractions handling is now the slowest part @~20% of the time.
Merge pull request #434 from larsmans/faster-word_tokenize

improve word_tokenize speed
removed stale test framework
Merge pull request #432 from dougalg/master

Changes to wordnet lowest_common_hypernyms
Merge pull request #425 from pfeyz/patch-1

Explicitly mention setuptools 0.6 in install.rst
Merge branch 'master' of https://github.com/nltk/nltk
nltk works for setuptools 0.8 already; resolved issue #435