Move sorting to resource types; remove NavigatorItem as a scheme for preparing information for display and move to interfaces on resource types. Resources support sorting on all three display columns (but not reverse sorting yet).

Due to this, CreatureList, PlaceableList, and ItemList are obsolete and removed. IDrawableList has an entirely new purpose. Waiter uses generic calls to fill list boxes. BackgroundLoader simply builds classification structure.
Merge remote-tracking branch 'origin/master'