Implement a SimpleDBResourceTracker for usage in `view`

With the code imported from PolicyStat, the `neckbeard.cloud_resource:InfrastructureNode` object is configured as a [python-simpledb](https://github.com/winhamwr/python-simpledb?source=cr) object (using the winhamwr fork). This lets us use ORM-style access to the backend, which is pretty nice, but it might be too complex of an interface to implement for folks wanting to add other backends. The problem with extensibility is that the SimpleDB connection is configured via Meta parameters. I maybe figured out how to get around this by having `neckbeard.environment_manager:Deployment` is initialize the connection in the constructor there.

Instead of doing initialization in the constructor:

1. Use `neckbeard.resource_tracker:SimpleDBResourceTracker` to handle all of that. Figure out how that object and the environment manager should interface.

2. If doing 1 didn't require a ton of code, also see about finishing the implementation of `view` and throwing some tests on the ResourceTracker.