lib/connections: Refactor

1. Removes separate relay lists and relay clients/services, just makes it a listen address
2. Easier plugging-in of other transports
3. Allows "hot" disabling and enabling NAT services
4. Allows "hot" listen address changes
5. Changes listen address list with a preferable "default" value just like for discovery
6. Debounces global discovery announcements as external addresses change (which it might alot upon starting)
7. Stops this whole "pick other peers relay by latency". This information is no longer available,
   but I don't think it matters as most of the time other peer only has one relay.
8. Rename ListenAddress to ListenAddresses, as well as in javascript land.
9. Stop serializing deprecated values to JSON

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/2982

lib/model/model.go

@@ -24,6 +24,7 @@ import (
 	"time"
 
 	"github.com/syncthing/syncthing/lib/config"
+	"github.com/syncthing/syncthing/lib/connections"
 	"github.com/syncthing/syncthing/lib/db"
 	"github.com/syncthing/syncthing/lib/events"
 	"github.com/syncthing/syncthing/lib/ignore"
@@ -92,7 +93,7 @@ type Model struct {
 	folderStatRefs     map[string]*stats.FolderStatisticsReference            // folder -> statsRef
 	fmut               sync.RWMutex                                           // protects the above
 
-	conn              map[protocol.DeviceID]Connection
+	conn              map[protocol.DeviceID]connections.Connection
 	helloMessages     map[protocol.DeviceID]protocol.HelloMessage
 	deviceClusterConf map[protocol.DeviceID]protocol.ClusterConfigMessage
 	devicePaused      map[protocol.DeviceID]bool
@@ -137,7 +138,7 @@ func NewModel(cfg *config.Wrapper, id protocol.DeviceID, deviceName, clientName,
 		folderRunners:      make(map[string]service),
 		folderRunnerTokens: make(map[string][]suture.ServiceToken),
 		folderStatRefs:     make(map[string]*stats.FolderStatisticsReference),
-		conn:               make(map[protocol.DeviceID]Connection),
+		conn:               make(map[protocol.DeviceID]connections.Connection),
 		helloMessages:      make(map[protocol.DeviceID]protocol.HelloMessage),
 		deviceClusterConf:  make(map[protocol.DeviceID]protocol.ClusterConfigMessage),
 		devicePaused:       make(map[protocol.DeviceID]bool),
@@ -277,7 +278,7 @@ type ConnectionInfo struct {
 	Paused        bool
 	Address       string
 	ClientVersion string
-	Type          ConnectionType
+	Type          string
 }
 
 func (info ConnectionInfo) MarshalJSON() ([]byte, error) {
@@ -289,7 +290,7 @@ func (info ConnectionInfo) MarshalJSON() ([]byte, error) {
 		"paused":        info.Paused,
 		"address":       info.Address,
 		"clientVersion": info.ClientVersion,
-		"type":          info.Type.String(),
+		"type":          info.Type,
 	})
 }
 
@@ -308,7 +309,7 @@ func (m *Model) ConnectionStats() map[string]interface{} {
 			versionString = hello.ClientName + " " + hello.ClientVersion
 		}
 		ci := ConnectionInfo{
-			ClientVersion: versionString,
+			ClientVersion: strings.TrimSpace(versionString),
 			Paused:        m.devicePaused[device],
 		}
 		if conn, ok := m.conn[device]; ok {
@@ -1004,7 +1005,7 @@ func (m *Model) GetHello(protocol.DeviceID) protocol.HelloMessage {
 // AddConnection adds a new peer connection to the model. An initial index will
 // be sent to the connected peer, thereafter index updates whenever the local
 // folder changes.
-func (m *Model) AddConnection(conn Connection, hello protocol.HelloMessage) {
+func (m *Model) AddConnection(conn connections.Connection, hello protocol.HelloMessage) {
 	deviceID := conn.ID()
 
 	m.pmut.Lock()
@@ -1021,7 +1022,7 @@ func (m *Model) AddConnection(conn Connection, hello protocol.HelloMessage) {
 		"deviceName":    hello.DeviceName,
 		"clientName":    hello.ClientName,
 		"clientVersion": hello.ClientVersion,
-		"type":          conn.Type.String(),
+		"type":          conn.Type,
 	}
 
 	addr := conn.RemoteAddr()