(Change): getUserByUsername returns null when username does not exist instead of a User object with invalid id.

(Add): method in UserAccountDAO for returning the user password.
(Add): JettyServer development server.
(Add file): log4j.properties
(Add file): resources/db.conf
(Add class): SignInServlet

(Modify): Add methods connect and disconnect to interface UserAccountDAO.
(Modified): method getUserByUsername retrieves the accounts associated with the user.