* Track upload and download data.
 * Emulate a UDP server in the UDP tracker tests rather than communicating with the Internet.
 * Make use of sparse file regions in download data for faster hashing. This is available as whence 3 and 4 on some OS?
 * When we're choked and interested, are we not interested if there's no longer anything that we want?
 * dht: Randomize triedAddrs bloom filter to allow different Addr sets on each Announce.
 * dht: Verify that the triedAddrs bloom filter is working well, github's willf made a bunch of changes.
 * Rearrange the local-peer choked/interested status flags to be more natural to read.
 * Check that pruning is working correctly. worstConns sorting might need an adjustment to how it factors in the good/unwanted chunks ratio.
 * data/blob: Deleting incomplete data triggers io.ErrUnexpectedEOF that isn't recovered from.
 * UL/DL rate-limiting.
 * Handle Torrent being dropped before GotInfo.