Better programmatic configuration.

- Dispatcher servlets and their contexts are now easier to configure.

- Moved all resources to test directories to better reflect real-world use cases.

- Added tests that start up Jetty and used retrofit to make a sequence of API calls.

- Fixed bug in rhizome utils that was causing unhappiness when a configuration was not found.

- Fixed bug in rhizome configuration service that was prevent configurations from being properly updated.

- Added toString method for simple configuration key.

- Added JacksonConverter based on square retrofit converter, but with some additional handling for null bodies.
Afterburner is a for free 15 - 25% perf increase by using byte code generation for data binding.

Guava module lets us freely serialize Java types to JSON when making service to service calls without worrying about it. This is useful for optional parameters since Optional<SomeClass> param can be omitted and turns into an Optional.absent() instead of causing a serialization error.