Drop xerrors and missinggo/slices dependency for Client (#572)
Drop xerrors and missinggo/slices dependency for Client (#572)

* Drop xerrors and missinggo/slices dependency for Client

Made `BadPeerIPs` inlineable since I changed `badPeerIPsLocked` anyway. Also eliminated an extra torrentsAsSlice copy since Go wasn't smart enough to figure it out.
anacrolix/torrent,anacrolix/torrent