Take Aaron's review comments into account.

* bzrlib/transport/http/_urllib2_wrappers.py:
(HTTPRedirectHandler.http_error_301): Fix bug #88780.

* bzrlib/transport/http/__init__.py:
(HttpTransportBase._get): Fix doc string.

* bzrlib/transport/__init__.py:
(do_catching_redirections): Raise TooManyRedirections instead of
requiring an exception as a parameter.

* bzrlib/tests/test_http.py:
(TestHTTPRedirections.setUp): Simplified.
(TestHTTPRedirections.test_read_redirected_bundle_from_url): New test.
(TestDoCatchRedirections): New tests.

* bzrlib/tests/HTTPTestUtil.py:
(TestCaseWithRedirectedWebserver): New class factored out from
test_http.TestHTTPRedirections.

* bzrlib/errors.py:
(TooManyRedirections): New exception.

* bzrlib/bzrdir.py:
(BzrDir.open_from_transport.redirected): Catch TooManyRedirections.

* bzrlib/bundle/__init__.py:
(read_bundle_from_url.redirected_transport): Catch TooManyRedirections.