Adding prompts for templates, CSS, and JavaScript

This adds support for 

- Dust
- No template
- LESS
- SASS
- Stylus
- RequireJS
- Browserify


Known caveats:

1. Opting for no template still produces a controller with `res.render`
2. Stylus is not supported in devtools yet.
3. Devtools references dust as `dust`, but the dependency in the generator is `dustjs`
4. Template scaffolding doesn't take into account template choice.