Playdoh update

Phew! This is a massive change, but wiping out the main parts of the app and upgrading to the latest playdoh is hard work. Highly recommend looking at individual commits for this one.

I tried to separate out the commits into logical chunks for the most part. The major exception is with 61a8c3f, which moves all of the files from `apps` into `affiliates`, and 66c7c7f, which then deletes most of the code moved in the earlier commit. Rule of thumb: If it's not in the `facebook` or `shared` app, and isn't a model, it's not going to exist by the end of this.

Some other things to note:
- I removed the admin for pretty much everything because we're probably going to want to recreate them from scratch with new models anyway.
- Stats admin stuff went away completely, since we want to rely on GA for our stats views from now on.
- There are still some remnants of things to be removed or updated, such as leftover settings and static files, but I figured this was a decent stopping point, since locally I have the Facebook app working, and the tests pass. There will be followups that address these changes.
- `shared` is still a separate app from `base`. My intent is to get rid of `shared` eventually, with `base` replacing it.
- Models are stripped, but fields are preserved. Intent here is to create new apps and migrate the data over later.