Add flags and metric to ZT-managed routes.

include/ZeroTierOne.h

@@ -633,6 +633,16 @@ typedef struct
 	 * Gateway IP address (port ignored) or NULL (family == 0) for LAN-local (no gateway)
 	 */
 	struct sockaddr_storage via;
+
+	/**
+	 * Route flags
+	 */
+	uint16_t flags;
+
+	/**
+	 * Route metric (not currently used)
+	 */
+	uint16_t metric;
 } ZT_VirtualNetworkRoute;
 
 /**