Support for Google App Engine

Unfortunately the diff is really big since everything had to move and all third party libraries had to be added.

Here's what changed:
* App went inside `src/application`. Files added in `src/` are primarily for google.
* `settings.py` allows us to have dev, test, and prod settings! We can also use secret keys to do proper form submit testing locally.
* Additional third party libraries will have to be added to `lib/` for google to be happy. We could alternatively setup virtual references for local development but I haven't gotten that far.

Things I don't know yet:
* The smoothness of the setup workflow for new contributors - I'm sure I'm missing steps, especially what happens after you install the google SDK and are asked to authenticate.

Example app this is based on: https://github.com/kamalgill/flask-appengine-template