Add handling of the HTTP Date header

runtime/bin/http.dart

 // Copyright (c) 2012, 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.
 
 /**
  * HTTP status codes.
  */
 interface HttpStatus {
   static final int CONTINUE = 100;
   static final int SWITCHING_PROTOCOLS = 101;
@@ skipping 259 matching lines @@
 
   /**
    * Remove all values for the specified header name. Some headers
    * have system supplied values and for these the system supplied
    * values will still be added to the collection of values for the
    * header.
    */
   void removeAll(String name);
 
   /**
+   * Gets and sets the date. The value of this property will
+   * reflect the "Date" header
+   */
+  Date date;
+
+  /**
    * Gets and sets the expiry date. The value of this property will
    * reflect the "Expires" header
    */
   Date expires;
 
   /**
    * Gets and sets the host part of the "Host" header for the
    * connection.
    */
   String host;
@@ skipping 245 matching lines @@
    */
   InputStream get inputStream();
 }
 
 
 class HttpException implements Exception {
   const HttpException([String this.message = ""]);
   String toString() => "HttpException: $message";
   final String message;
 }