* swarm/network: simplify kademlia/hive; rid interfaces * swarm, swarm/network/stream, swarm/netork/simulations,, swarm/pss: adapt to new Kad API * swarm/network: minor changes re review; add missing lock to NeighbourhoodDepthC
* swarm: propagate ctx, enable opentracing * swarm/tracing: log error when tracing is misconfigured