New Features
* Add docstrings
* Handle robots.txt parsing with `urllib.RobotFileParser`
* `User-Agent` header is exposed as `FAAPI.user_agent` property
Changes
* `FAAPI.last_get` uses UNIX time
* `FAAPI.check_path` doesn't raise an exception by default
* `FAAPI.login_status` does not raise an exception on unauthorized
* Remove crawl delay error
* Improve download of files