fixes #221, initial sync*, async, async* implementation

lib/src/server/server.dart

 // Copyright (c) 2015, the Dart 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 file.
 
 /// Development server that compiles Dart to JS on the fly.
 library dev_compiler.src.server;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
@@ skipping 281 matching lines @@
   return new _ExistingSourceUriResolver(new ResourceUriResolver(provider));
 }
 
 /// A UriResolver that continues to the next one if it fails to find an existing
 /// source file. This is unlike normal URI resolvers, that always return
 /// something, even if it is a non-existing file.
 class _ExistingSourceUriResolver implements UriResolver {
   final UriResolver resolver;
   _ExistingSourceUriResolver(this.resolver);
 
-  Source resolveAbsolute(Uri uri) {
-    var src = resolver.resolveAbsolute(uri);
+  Source resolveAbsolute(Uri uri, [Uri actualUri]) {
+    var src = resolver.resolveAbsolute(uri, actualUri);
     return src.exists() ? src : null;
   }
   Uri restoreAbsolute(Source source) => resolver.restoreAbsolute(source);
 }
 
 final _log = new Logger('dev_compiler.src.server');
 final _earlyErrorResult = new CheckerResults(const [], null, true);