Fix display of all-day events if there's more than one all-day event.

If there are two all-day events for the same day, previously both events
would be displayed with the same title. Fix that by replacing the logic
that attempted to fix sorting issues by a real sort of the event info
list.

Fixes issue CYAN-137.

Change-Id: I3bfc4124c619a9a922ae9d20cc8e1fba08db188e