Cupertino: Mark as new/unread, sync with timeline

[KimihikoAkayasaki]

Strategy:

• Keep a list of hashes of all [read, supported] objects
• Add wasSeen to each sp. object, search for own hash in the list
• Add allSeen to collections for quicker backend access

[KimihikoAkayasaki]

Upcoming events for the same day should be hidden after the day has ended, unless their timeFrom > end.

[KimihikoAkayasaki]

Essentially done with 42cec9c25b8d134c076b79c7b669e8a3b3f01656 May be worth adding to the cupertino app implementation