Consistent use of Cancel & Done vs. Back & Done

[ccmitchellusa]

iOS app users Cancel & Done for buttons on all detail pages where changes can be made for an item. Cancel backs out any changes user may have made on the view, Done commits them. Current app has inconsistent header buttons and cancel doesn't cancel. Note: The app controller/navication controller needs to be flexible here. Some apps will want no Done button, and just a Back which auto-saves, or selecting items in lists auto commits and pops to prev view.

[eric-wang]

fix add/detail view header in commit: https://github.com/cjolif/dojo-todo-app/commit/0d7b0bbd0d448143ecc2196498d0f81eb3fe49a6