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/packets.go

@@ -10,8 +10,8 @@
 package discover
 
 const (
-	AnnouncementMagic = 0x9D79BC39
-	QueryMagic        = 0x2CA856F5
+	AnnouncementMagic = 0x9D79BC40
+	QueryMagic        = 0x2CA856F6
 )
 
 type Query struct {
@@ -25,12 +25,13 @@ type Announce struct {
 	Extra []Device // max:16
 }
 
-type Device struct {
-	ID        []byte    // max:32
-	Addresses []Address // max:16
+type Relay struct {
+	Address string // max:256
+	Latency int32
 }
 
-type Address struct {
-	IP   []byte // max:16
-	Port uint16
+type Device struct {
+	ID        []byte   // max:32
+	Addresses []string // max:16
+	Relays    []Relay  // max:16
 }