- Daily limits are no longer inherited - each deck limits its own
cards, and the selected deck enforces a maximum limit.
- Fetching of review cards now uses a single query, and sorts in advance.
In collections with a large number of overdue cards and decks, this is
faster than iterating over each deck in turn.
- Include interday learning count in review count & review limit, and
allow them to be buried.
- Warn when parent review limit is lower than child deck in deck options.
- Cap the new card limit to the review limit.
- Add option to control whether new card fetching short-circuits.
- split new card fetch order and subsequent sort order; use latter
when building queues
- default to spacing siblings when burying is off, with options to
show each sibling in turn, and shuffle the fetched cards
