Tutorial feedback

Collected feedback about the [Todo tutorial](http://foamdev.com/tutorial/todo/0-intro) from TorontoJS and elsewhere.
- [x] Note briefly that templates can live in their own files, and show how to do it.
- [ ] Provide a (categorized, probably) list of DAO implementations - real DAOs, decorators, and others.
- [ ] Someone asked how we support search against LocalStorage, when LocalStorage doesn't support search.
- [x] `$EDITOR` and `$PROJECT` are confusing to non-Unix users. I should explain and probably edit around those.
- [x] Make clear that FOAM is in JS, and that I mention and show Java only as a point of reference.
- [x] Make clear that `Todo.js` and `TodoApp.js` are completely separate files. **Use directory tree diagrams.**
- [x] Make clear that we want to just run the server perpetually in the background.
- [x] Mention that the commands, and especially the Python commands, won't work on Windows.
- [x] People are surprised and confused when they open the model-only GUI; it looks nearly identical to the previous link to the finished app. Clarify that that's what they should be expecting.
- [x] Document `index.html`'s magical behavior, explain a bit about how it works.
- [ ] Explain the 404s in the console, especially that they're harmless.
- This first comes up when we're loading our `Todo` model alone with `index.html`.
- [x] Port the tutorial to U2 views.
- [x] Expand the tutorial to include an example of adding a Node.js server.
- [ ] Expand the tutorial further to include authentication on that server.
- [ ] Document, probably as part of the latter expansion above, the auth system.