### Added
- `client.listening` property to signal whether TCP server is listening
for incoming
connections.
### Changed
- Merged `Swarm` class into `Torrent` object. Properties on
`torrent.swarm` (like
`torrent.swarm.wires`) now exist on `torrent` (e.g. `torrent.wires`).
- `torrent.addPeer` can no longer be called before the `infoHash` event
has been
emitted.
- Remove `torrent.on('listening')` event. Use `client.on('listening')`
instead.
- Remove support from `TCPPool` for listening on multiple ports. This
was not used by
WebTorrent and just added complexity. There is now a single `TCPPool`
instance for the
whole WebTorrent client.
- Deprecate: Do not use `client.download()` anymore. Use `client.add()`
instead.
- Deprecate: Do not use `torrent.swarm` anymore. Use `torrent` instead.
### Fixed
- When there is a `torrent.on('error')` listener, don't also emit
`client.on('error')`.
- Do not return existing torrent object when duplicate torrent is
added. Fire an
`'error'` event instead.
- Memory leak of `Torrent` object caused by `RarityMap`
- Memory leak of `Torrent` object caused by `TCPPool`
- `client.ratio` and `torrent.ratio` are now calculated as `uploaded /
received` instead
of `uploaded / downloaded`.
bittorrent-swarm and the Torrent object in webtorrent are very coupled.
It doesn't make much sense to publish them separately, as
bittorrent-swarm can't be used independently.
