Revision 1845942

Add a test to check if our client works with GitHub's SVN bridge.

Because testing this involves connecting to a remote server, which our
test suite did not do up to now, the new test is skipped unless such
remote connections are explicitly allowed in the test run.

* Makefile.in (check): Add new option ALLOW_REMOTE_HTTP_CONNECTION.

* build/run_tests.py: Update docstring.
  (create_parser): Add option --allow-remote-http-connection.
  (TestHarness._init_py_tests): Propagate the option to test fixtures.

* subversion/tests/cmdline/dav_tests.py
  (connect_to_github_server): New test case.

* subversion/tests/cmdline/svntest/main.py
  (is_remote_http_connection_allowed): New predicate function.
  (_create_parser): Add option --allow-remote-http-connection.
  (TestSpawningThread.run_one): Propagate the option to subprocesses.