TODO

! update docs

PRs
  ? NIP-91 AND filters

possible features
  HyperLogLog support in COUNT, as per NIP-45
  asynchronous plugins (multiple in flight at once)
  slow-websocket connection detection and back-pressure
  in sync/stream, log bytes up/down and compression ratios
  archival mode (no deleting of events)

rate limits (maybe not needed now that we have plugins?)
  event writes per second per ip
  max connections per ip (nginx?)
  max bandwidth up/down (nginx?)
  log IP address in sendNoticeError and elsewhere where it makes sense
  ? events that contain IP/pubkey/etc block-lists in their contents
  ? limit on total number of events from a DBScan, not just per filter
  ? time limit on DBScan

misc
  ? periodic reaping of disconnected sockets (maybe autoping is doing this already)