Cleanup and implementation of Update / Notification parser / serializers.

testdata/server.textpb

@@ -0,0 +1,10 @@
+router_id: "10.0.0.1"
+local_asn: 65000
+listen_endpoints {
+    address: "127.0.0.1"
+    port: 179
+}
+listen_endpoints {
+    address: "[::1]"
+    port: 179
+}