Code review comment for lp:~widelands-dev/widelands/net-relay

So much for: "[Prequisite branches] changes will not be shown in the diff."
The changes to NetHost, NetClient and the new interface classes are also at:
https://code.launchpad.net/~widelands-dev/widelands/nethost-split/+merge/332385

Maybe they will disappear from the diff here after the other branch is merged into trunk.