An entity mirroring application for Django

This PR includes the first working version of django-entity, an app that syncs and mirrors entities in a Django application. It provides the ability to define relationships from the models in your application, metadata about your entities, and information about active or inactive entities and their relationships.

This PR provides the first unoptimized version of this app.

A formatted README can be viewed here https://github.com/wesleykendall/django-entity