Fixes for https://github.com/krakenjs/generator-kraken/issues/115

- [x] Only add .bowerrc when a templateModule is picked, this is a separate prompt option now
- [x] Middleware for serverError and fileNotFound will not be added by default, as they assume templates with error messages today
- [x] Controllers will just do `res.json` when no templateModule selected
i like the idea of the `html-izing` response. I can make that change.