Fix misspelling
Merge pull request #357 from kraai/fix/missp

Fix misspelling
Fix typos
Merge pull request #360 from kraai/fix-typos

Fix typos
Add a Tor test template and several experimental tests.

tor_exit_ip_check fetches the egress IP by way of IP reflector service
and compares with the advertised ORPort

tor_http_requests fetches a set of URLs over each exit in the consensus.

tor_tls_handshake performs a TLS handshake to a set of endpoints for
each exit in the consensus. Unfortunately, python openssl bindings are
rather broken and this test does not correctly obtain the negotiated
cipher suite.
Refactor and rename dispatcher MetaAttacher to AttacherDispatcher.

Fixes a bug where the MetaAttacher was instanced for each instance of a NetTest.
Handle ungraceful restart
Use OnionRoutedAgent instead of OnionRoutedTrueHeadersAgent

FIXME: A bug causes requests made with the OnionRoutedTrueHeaders
agent to fail with PartialDownloadError. This is a workaround.