Lifetime of FragmentTuners scoped to activity.

Add support for resetting with new state from directory fragment.
Update Model to use an EventListener.
Eliminate documentPick handling from base activity and directory fragment...
    Plum document picking directly from UserInputHandler to FragmentTuner instances.
Add new EventHandler internface (returns void, more semantic meaning that Consumer<T>).
Replace ModelUpdateListener interface with EventHandler.
Make DocumentAdapters return EventHandler<Model.Update> instead of
    implementing ModelUpdateListener.
Move Activity specific FragmentTuner impls along side respective activities.

Change-Id: Ia6a5ab00ede685f7418773ed865d8c51e4125330
27 files changed