1. Removes state variables:
- totalWeightedStakeThisEpoch
- totalFeesCollectedThisEpoch
- numActivePoolsThisEpoch
2. No longer indexes by epoch % 2
3. Renamed event StakingPoolActivated → StakingPoolEarnedRewards.
4. Renamed structs:
- ActivePool → PoolStats. This holds stats for a pool that earned rewards.
- UnfinalizedState → AggregatedStats. This aggregates stats from the former struct.
- No longer an upper limit on how many makers can be in a pool.
- No longer a handshake for a maker to join a pool.
- No longer any special powers given to makers.
- Pool Id starts at 1 and increments by 1.