incompatibility with Twisted 13.1.0 -- twisted.web.client has no attribute '_parse'

[Zooko]

zooko@spark ~/playground/foolscap $ trial foolscap.test.test_negotiate.Versus.testVersusHTTPClientUnauthenticated
foolscap.test.test_negotiate
  Versus
    testVersusHTTPClientUnauthenticated ...                             [ERROR]

===============================================================================
[ERROR]
Traceback (most recent call last):
  File "/home/zooko/playground/foolscap/foolscap/test/test_negotiate.py", line 289, in testVersusHTTPClientUnauthenticated
    d = self.connectHTTPClient(portnum)
  File "/home/zooko/playground/foolscap/foolscap/test/test_negotiate.py", line 200, in connectHTTPClient
    return getPage("http://127.0.0.1:%d/foo" % portnum)
  File "/home/zooko/playground/foolscap/foolscap/test/test_negotiate.py", line 83, in getPage
    scheme, host, port, path = client._parse(url)
exceptions.AttributeError: 'module' object has no attribute '_parse'

foolscap.test.test_negotiate.Versus.testVersusHTTPClientUnauthenticated
-------------------------------------------------------------------------------
Ran 1 tests in 0.017s

FAILED (errors=1)
zooko@spark ~/playground/foolscap $ git log | head
commit d34838ec99023eabef178110a74ca0c97b69603a
Author: Brian Warner <warner@lothar.com>
Date:   Mon Jun 18 19:25:44 2012 -0700

    release Foolscap-0.6.4

commit 9d49310a585828b8e9ea0b47cd1089be53efb04c
Author: Brian Warner <warner@lothar.com>
Date:   Mon Jun 18 19:25:12 2012 -0700

zooko@spark ~/playground/foolscap $ python -c 'import twisted; print twisted.__version__'
13.1.0

[Brian Warner]

Patch (from ​pr#14) rebased and landed in [9a87c87]