Resolve schema validation

Last week, I went down the route of defining a schema for each state using MetaYaml and making that a required part of registering the state. I consider this implementation to be unsuccessful / in need of a rethink.

What I was trying to do is two parts:

1. Make it easy to test your state file against the spec.
1. Have an internal mechanism for translating the state file into data objects understood by the region, and vice versa.

The current implementation addresses the first part successfully and completely fails at the second. All of the regions address the second right now by building arrays inside of `get_current_data()`.

What I'd like is a way of defining the schema for each region's data objects such that it works for validation *and* translation.