- saveKnownNodes replaced the repeated pickle.dump
- with knownNodesLock instead of acquire/release
- outgoingSynSender had an unnecessary loop during shutdown causing
excessive CPU usage / GUI freezing
- rearranged code to reduce cyclic dependencies
- doCleanShutdown is separated in shutdown.py
- shared queues are separated in queues.py
- some default values were moved to defaults.py
- knownnodes partially moved to knownnodes.py