python/bllipparser/RerankingParser.py: minor doc update
From the Dept. of Redundancy Dept.
python/bllipparser/RerankingParser.py: improve PEP8 compliance
python/bllipparser/RerankingParser.py: even more PEP8 compliance
python/bllipparser/RerankingParser.py: Tree.labelSuffix -> Tree.label_suffix
python/bllipparser: Initial StanfordDependencies integration
RerankingParser now has sd_tokens() which converts and caches SD Tokens
ParsingShell has a simple sdparse command which prints the tokens.

Early adopters note: Currently requires bleeding edge version of
PyStanfordDependencies.
python/bllipparser/RerankingParser.py: fix renamed SWIG type
first-stage/PARSE/swig/wrapper.i: run input through tokenizer
sentRepsFromString and sentRepsFromFile weren't doing this.
Also fix a typo.
python/bllipparser/RerankingParser.py: don't acquire inner InputTrees
This can cause segfaults since the outer tree frees the inner ones when
it is freed.
Also moved sd_tokens() method since it was in an unintended place.
Minor doc/comment updates.
Python doc updates to cover new Tree methods
This includes label now being a property, __getitem__ for tree navigation,
all_subtrees, and is_preterminal.
python/tests: New testsuite for Python functionality
Integrated with Travis-CI. Tests are currently just doctest-based
(better than nothing!). Run with:

    % nosetests --with-doctest -dv python/tests/

in the repository's top-level directory.