This release improves CPU, memory and network utilisation in larger clusters.

Instead of broadcasting topology changes to every peer, they are sent to (2log2) neighbours, so in a very sparse cluster the information will take a little longer to reach everyone but it drops the workload on cluster formation from O(N^2) to O(NlogN).

Also we slowed down the rate at which new connections are added: 100 connections will now take 4 seconds.

Full list of changes https://github.com/weaveworks/mesh/compare/v0.3...v0.4