persistence.

archivables.

providing the entity to be updated. New implementation search for the
entity using the IObservableValue provided to sets the new value. Also
rename the new implementation into ManagerUpdateValueStrategy.

is add or when get() is called. Detach listener when dirty.

entities are added, updated or removed or when a dependencies changed.

dependencies  from ObservableTracker. Instead, the dependency list is
provided in constructor.