game info view now uses segmented control

additional changes
- the view now also displays information about the current board position
- move statistics are for the entire game (not just for the current board
  position); this reverts a change made in one of the more recent commits
remember which info type was last selected in game info view
fix bug introduced in dd0e884: ScoringModel not yet available

Since dd0e884 NavigationBarController is initialized at an early time during
application launch where the ScoringModel object does not exist yet. This
bugfix makes sure that NavigationBarController is configured with the model
object at a later time.