Fix for BuySellAds regex, make python_raw driver into Python package

Apologies for the multiple changes in this pull request. Changes:

1) Fix in apps.json for BuySellAds html regex. It previous contained catastrophic backtracking, hanging execution on analysis. (https://github.com/ElbertF/Wappalyzer/issues/711)
2) PEP8 formatting cleanup for python_raw driver.
3) Add setup.py to python_raw driver, allowing it to be installed as a Python package.