Commit long standing modifications before merging bzr.dev.

* bzrlib/transport/http/_pycurl.py:
(PyCurlTransport._set_curl_options): Enable peer verification
again.
(get_test_permutations): Add a permutation against an https test
server if available.

* bzrlib/tests/ssl_certs/__init__.py: 
Not a script anymore, update copyright.

* bzrlib/errors.py: 
Delete unused import.