Orchestration updates

There's a few things here:

 - adds supports for another couple of features from the Orchestration API.
 - works around a bug that I think is actually in Heat, but I haven't gotten confirmation there.
 - renames classes to conform to the rest of the lib
 - adds a basic unit test for the orchestration service.

Regarding the unit test, I would've gone further but `StubConnection` is already kind of insane. Would you be adverse to a pull request that lets unit tests stub out expected requests/responses inline rather than emulating entire API's with a giant block of nested if-statements?