Vertex

- Switch to setuptools; this should resolve issues with Vertex being
installed through pip, particularly as a dependency of something else.
- Numerous other small fixes and cleanups.

- Remove use of deprecated Twisted APIs from the test suite and improve
some error handling as a necessary consequence.
- Use twisted.internet.ssl instead of epsilon.sslverify.
- Remove an implementation of deferLater.

- Moved JUICE implementation into Epsilon.
- Removed dependency on Nevow's formless.
- Clarify licensing terms.
- Fix bugs on 64-bit platforms.
- removed buggy legacy non-TLS options which would break negotiation with
OpenSSL 0.9.8a.
- Deprecated twisted test APIs removed.
- First phase of integration with twisted.cred; vertex endpoints can now be
authenticated against a Twisted UsernamePassword cred authenticator.

- Initial release.