• new endpoint: v2/churns
  
• save transfers to db by default enabling v2/balance by default.
  
• v2/balance?height=n or v2/balance?timestamp=t
  
• event_id: stable ordering across machines in v2/actions
  
• event_id: db users (e.g. flipside) can use event_id instead of block_timestamp for sorting or to notice duplicates.
  
• optimized and simplified v2/thornames db queries
  
• Overall ~12% db size increase: reduce by removing unused depths maps, increase by transfers and event ids.
  
• Causes a db resync.