Massive refactoring work to Django

OK. This still isn't something I'm 100% comfortable with, but I spent some trying to try out integration on orgs and jurisdictions. This is basically to start discussion on a method to serve out data that looks like it's actually working.

It's even got field limiting working (a few recursion issues, but I have some ideas once we're sure this is a technique we're all cool with) such that:

`'http://127.0.0.1:8000/ocd-organization/58466132-9d91-42df-84a6-7861b16ff879/?fields=memberships.organization.memberships.person.name'` results in:

Which gets all the names of all the people who hold a membership in this org (but recursing into the org through memberships, just to prove the point. Not sure that's all that useful)

```json
{
    "memberships": [
        {
            "organization": {
                "memberships": [
                    {
                        "person": {
                            "name": "Lynn Gattis"
                        }
                    },
                    [...]
                  ]
                  [...]
                }
                [...]
 ...
}
```

Anyway, the code is young, but it's starting to look promising. Anyone have thoughts on the technique? @twneale @jamesturk