Plac

New feature, requested by John Didion: if the type of an argument is not
specified but there is a default value, it is inferred from it. This is
experimental and works only for Python literal types.
Fixed a bug caused by arguments with default None in newer versions of argparse.
Added a `gh-pages` branch with the documentation, as suggested by Ryan Gonzalez.
Extended the Travis testing to Python 3.6. Python 2.6 still works but it is
untested and therefore deprecated.

Solved an issue with non-ASCII characters; now any UTF-8 character
can go in the help message. Added support for `--version` in plac.call.
Modernized the changelog https://keepachangelog.com/

Removed a usage of `print >>` that was breaking Python 3, signaled
by Quentin Pradet

Removed use_2to3 in setup.py which was breaking Python 2, signaled
by Quentin Pradet

Fixed the tests on Python 3 and produced a universal wheel instead of
relying on 2to3. Enabled Travis builds for Python 3.3, 3.4, 3.5

Moved the repository from GoogleCode to GitHub. Included the doc fixes
by Nicola Larosa and polished the code base to be PEP 8 compliant.
Enabled Travis builds for Python 2.6 and 2.7