* More third-party/ cleanup:
System.FilePath? is moved into third-party/ and upgraded to use Neil Mitchell's maintained branch.
Pugs.Rule.* is no more, as we are no longer forking Parsec.
(Four more cleanups to go before we complete the third-party/ move as suggested by allison++.)
(Four more cleanups to go before we complete the
third-party/ move as suggested by allison++.)