[B] Fixing types for occurrence model.
[F] Deprecating fields in Event model that are now in Occurrence. Loses sorting for now.
[B] Creating occurrences on the same page as their events in update script.
[B] Deprecated functions weren't properly accessing the first Occurrence model.
[F] Adding some sorting. Needs to be expanded for search queries and everything else.
[B] Fixing how we query for events by occurrences.
[F] Making the sorting mechanism flexible.
[F] Moving some old Event functions to the new Occurrence model.