This class authenticates users against a stored username/password in the database. It depends upon the schema laid out in the setup folder.
At present, it works with the Session DB system to handle authentication and storing information in the session.
Password hashing/verification is done using PHP's built-in password_hash() and password_verify(). Support for PHP 5.3 and 5.4 is achieved by using the compatibility library "Password_Compat", which is available using Composer (via Packagist).