Furl v2.1.1.

Fixed: Export metadata variables (furl.__title__, furl.__version__, etc).
Added: scheme, host, netloc, and origin as parameters to furl.remove().
Changed: Homogenize parameter order across furl.add(), furl.set(), and furl.remove().
Changed: furl.origin can be assigned None. This has the same behavior as furl.remove(origin=True).