Add Python 3.x support
Merge remote-tracking branch 'origin/master' into issue-12
[setup] Add six as a dependency
[pynliner] Support Python3.x
More work on Python 3 support - breaks tests

Changed BeautifulSoup from version 3 to 4, for Py3 support.  Switched
around many names to Py3 versions.  BeautifulSoup 4 seems to behave
slightly differently, so many tests fail.  But I fixed all the tests
that error.
Merge remote-tracking branch 'origin/master'
Fix a couple of test cases, from BeautifulSoup4