iPhone: Apprentice: Checklists: Add the place to type in check list name
iPhone: Apprentice: Checklists: Display keyboard right away on add screen
iPhone: Apprentice: Checklists: Only enable "done" button when user types text
iPhone: Apprentice: Checklists: Refactor enable/disable done button code
iPhone: Apprentice: Checklists: Make ChecklistViewController a delegate of AddItemViewController so we can do the work there
iPhone: Apprentice: Checklists: Via delegate, add the new checklist item