Add argparse to setup.py

argparse is not available in python 2.6 by
default.
Python 3 compatibility

Including converting one of the test data files to
UTF-8. It was Windows encoded which failed with
python 3's file.read encoding.
Add support for tox

Run 'tox' to test against python 2.6, 2.7, and 3.3
Merge pull request #7 from ziadsawalha/tox

Tox support +  python 3.3 compatibility