p2p/discover: new endpoint format

This commit changes the discovery protocol to use the new "v4" endpoint
format, which allows for separate UDP and TCP ports and makes it
possible to discover the UDP address after NAT.

p2p/discover/table.go

@@ -220,7 +220,7 @@ func (tab *Table) bondall(nodes []*Node) (result []*Node) {
 	rc := make(chan *Node, len(nodes))
 	for i := range nodes {
 		go func(n *Node) {
-			nn, _ := tab.bond(false, n.ID, n.addr(), uint16(n.TCPPort))
+			nn, _ := tab.bond(false, n.ID, n.addr(), uint16(n.TCP))
 			rc <- nn
 		}(nodes[i])
 	}
@@ -299,12 +299,7 @@ func (tab *Table) pingpong(w *bondproc, pinged bool, id NodeID, addr *net.UDPAdd
 		tab.net.waitping(id)
 	}
 	// Bonding succeeded, update the node database
-	w.n = &Node{
-		ID:       id,
-		IP:       addr.IP,
-		DiscPort: addr.Port,
-		TCPPort:  int(tcpPort),
-	}
+	w.n = &Node{ID: id, IP: addr.IP, UDP: uint16(addr.Port), TCP: tcpPort}
 	tab.db.updateNode(w.n)
 	close(w.done)
 }