lively.next todo list tutorial
1. Creating a todo item
In the first step we create a todo item as a new object, and customize its appearance and define a "done" property for it.
2. Creating a todo list container
We use assign a layout to a container object so that it acts as the todo list.
3. Adding todo items.
To create new items inside the todo list we add a button and connect its "fire" event to the container. By copying the existing todo item we can create and append new items.