- Store received chunks in temp files
   - Don't allocate from heap for unneeded chunks
   - Remove peer count restriction for torrents with large pieces
   - Use priorities and rarest calculations to sort partials
   - Preserve p parameter in clear messages link

      - Drop queued outbound requests when choked
      - Redo some data structures and locking to hopefully prevent deadlock
      - Memory reduction part 3: Return partial pieces to PeerCoordinator when choked

                in preparation for more improvements