Add mDNS discovery to the Fletch compiler

pkg/mdns/lib/mdns.dart

 // Copyright (c) 2015, the Fletch project authors. Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE.md file.
 
 library mdns;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:io';
 import 'dart:typed_data';
 
 import 'package:mdns/src/native_extension_client.dart';
 import 'package:mdns/src/native_protocol_client.dart';
 import 'package:mdns/src/constants.dart';
+import 'package:mdns/src/packet.dart';
 
 export 'package:mdns/src/constants.dart' show RRType;
 export 'package:mdns/src/packet.dart' show ResourceRecord;
 
 /// Client for DNS lookup using the mDNS protocol.
 ///
 /// This client only support "One-Shot Multicast DNS Queries" as described in
 /// section 5.1 of https://tools.ietf.org/html/rfc6762
 abstract class MDnsClient {
   // Instantiate Client for DNS lookup using the mDNS protocol.
@@ skipping 27 matching lines @@
   ///
   /// The [name] must be the fully qualified name (that is including
   /// the domain '.local'); for example `printer.local`.
   ///
   /// The stream is closed after the timeout is reached.
   Stream<ResourceRecord> lookup(
       int type,
       String name,
       {Duration timeout: const Duration(seconds: 5)});
 }