R1:7e0ce0815435

Make various Drydock CLI/Allocator improvements

Summary:
- Remove EC2, RemoteHost, Application, etc., blueprints for now. They're very proof-of-concept and Blueprints are getting API changes I don't want to bother propagating for now. Leave the abstract base class and the LocalHost blueprint. I'll restore the more complicated ones once better foundations are in place.
- Remove the Allocate controller from the web UI. The original vision here was that you'd manually allocate resources in some cases…