Add additional trove classifiers to setup.py (#250)

- Document project as stable, ready for use in production environments
- Document project license

Helps library users know these values at a glance. These classifiers are
displayed on the PyPI page:

https://pypi.python.org/pypi/pycparser

For a complete list of trove classifiers, see:

https://pypi.python.org/pypi?%3Aaction=list_classifiers
1 file changed