Large refactoring/feature commit

1. Change listen addresses to URIs
2. Break out connectionSvc to support listeners and dialers based on schema
3. Add relay announcement and lookups part of discovery service

lib/discover/client_test.go

@@ -37,10 +37,8 @@ func TestUDP4Success(t *testing.T) {
 		Magic: AnnouncementMagic,
 		This: Device{
 			device[:],
-			[]Address{{
-				IP:   net.IPv4(123, 123, 123, 123),
-				Port: 1234,
-			}},
+			[]string{"tcp://123.123.123.123:1234"},
+			nil,
 		},
 	}
 
@@ -101,7 +99,12 @@ func TestUDP4Success(t *testing.T) {
 	wg := sync.NewWaitGroup()
 	wg.Add(1)
 	go func() {
-		addrs = client.Lookup(device)
+		pkt, err := client.Lookup(device)
+		if err == nil {
+			for _, addr := range pkt.This.Addresses {
+				addrs = append(addrs, addr)
+			}
+		}
 		wg.Done()
 	}()
 
@@ -117,7 +120,7 @@ func TestUDP4Success(t *testing.T) {
 	// Wait for the lookup to arrive, verify that the number of answers is correct
 	wg.Wait()
 
-	if len(addrs) != 1 || addrs[0] != "123.123.123.123:1234" {
+	if len(addrs) != 1 || addrs[0] != "tcp://123.123.123.123:1234" {
 		t.Fatal("Wrong number of answers")
 	}
 
@@ -138,10 +141,8 @@ func TestUDP4Failure(t *testing.T) {
 		Magic: AnnouncementMagic,
 		This: Device{
 			device[:],
-			[]Address{{
-				IP:   net.IPv4(123, 123, 123, 123),
-				Port: 1234,
-			}},
+			[]string{"tcp://123.123.123.123:1234"},
+			nil,
 		},
 	}
 
@@ -197,7 +198,12 @@ func TestUDP4Failure(t *testing.T) {
 	wg := sync.NewWaitGroup()
 	wg.Add(1)
 	go func() {
-		addrs = client.Lookup(device)
+		pkt, err := client.Lookup(device)
+		if err == nil {
+			for _, addr := range pkt.This.Addresses {
+				addrs = append(addrs, addr)
+			}
+		}
 		wg.Done()
 	}()