Tracking model changes across M2M relationships

$ virtualenv --no-site-packages ve
$ source ve/bin/activate
(ve)$ pip install -r requirements.pip
(ve)$ cd example_project
(ve)$ ./manage.py test app

Guiding principles

1. Master doesn't need to know what slaves are replicating data.
2. Master always keeps a grand master copy of all data.
3. Slaves maintain duplicated, perhaps expanded, data set.