* syncthing/pr/1995:
Add switch to disable relays
Do not start relay service unless explicitly asked for, or global announcement server is running
Add dynamic relay lookup (DDoS relays.syncthing.net!)
Discovery clients now take an announcer, global discovery is delayed
Expose connection type and relay status in the UI
Add dependencies (fixes#1364)
Check relays for available devices
Add incoming connection relay service
Add unsubscribe to config
Connections have types
Large refactoring/feature commit
c87faace6b