Blueprints (WIP)

Presently blueprint.js contains a load of special cases — these are just in there to get the tests in shape.

Next steps are:

- [ ] Convert blueprint to model-style constructor
- [ ] index.js in each blueprint exports a subclass of blueprint
- [ ] Blueprint.lookup + configurable load paths
- [ ] Blueprint#addRouteToRouter

See `tests/acceptance/generate-test.js` for more todos.