DisplayListWatcher: will process initializers for all values in nameList that have initializers. If no names in nameList have an initializer, the default one will be used. If any values in nameList have initializers, the default one won't be used.
ScreenNavigator: properly resizes active screen if auto sizing based on content, but the active screen is smaller than the explicit width or height
Header: proper measurement for centerItems
Drawers: Added open and close events (closes #754)