Typos found while adapting the chapter 2 tutorial

[pglewis]

https://marionette.gitbooks.io/marionette-guides/content/en/getting_started/tutorial/layouts.html

Near the end in layout.js onChildviewAddTodoItem still refers to this.ui, but the ui has been refactored out into the form view at this point. To get this to work I needed to add a parameter to the onChildviewAddTodoItem method and access ui via that object.

This also appears in the summary code:

https://marionette.gitbooks.io/marionette-guides/content/en/appendix/getting_started/tutorial/todo_app.html

[jdaudier]

/cc @scott-w

[pglewis]

https://marionette.gitbooks.io/marionette-guides/content/en/getting_started/tutorial/layouts.html

module.exports = TodoView; should be TodoList