chore(packaging): move files to match target file structure

modules/angular2/src/facade/async.dart

@@ -0,0 +1,39 @@
+library angular.core.facade.async;
+
+import 'dart:async';
+export 'dart:async' show Future;
+
+class PromiseWrapper {
+  static Future resolve(obj) => new Future.value(obj);
+
+  static Future reject(obj) => new Future.error(obj);
+
+  static Future<List> all(List<Future> promises) => Future.wait(promises);
+
+  static Future then(Future promise, success(value), Function onError) {
+    if (success == null) return promise.catchError(onError);
+    return promise.then(success, onError: onError);
+  }
+
+  static _Completer completer() => new _Completer(new Completer());
+
+  static void setTimeout(fn(), int millis) {
+    new Timer(new Duration(milliseconds: millis), fn);
+  }
+}
+
+class _Completer {
+  final Completer c;
+
+  _Completer(this.c);
+
+  Future get promise => c.future;
+
+  void complete(v) {
+    c.complete(v);
+  }
+
+  void reject(v) {
+    c.completeError(v);
+  }
+}