The notfification APIs now use NotificationSpec as their only parameter, which
contains all information (required and optional ones).
We no longer have separate methods and actions for SMS/EMAIL/GENERIC anymore.
The type of notification is important now, not how we received them technically.
They are now managed by the Activity, because the fragments
may be created and destroyed at any time and hece cannot
synchronize their date-state all the time.
Open issue: moving across the borders (first day with data,
current day)