Log Message:
Update to 1.8.0:

1.8.0
-----

- Issue #90: Add six.moves.shlex_quote.

- Issue #59: Add six.moves.intern.

- Add six.urllib.parse.uses_(fragment|netloc|params|query|relative).

- Issue #88: Fix add_metaclass when the class has __slots__ containing
  "__weakref__" or "__dict__".

- Issue #89: Make six use absolute imports.

- Issue #85: Always accept *updated* and *assigned* arguments for wraps().

- Issue #86: In reraise(), instantiate the exception if the second argument is
  None.

- Pull request #45: Add six.moves.email_mime_nonmultipart.

- Issue #81: Add six.urllib.request.splittag mapping.

- Issue #80: Add six.urllib.request.splituser mapping.