Make FileInputStream and FileOutputStream actually asynchronous.

runtime/bin/file.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.
 
 
 /**
  * FileMode describes the modes in which a file can be opened.
  */
 class FileMode {
   static final READ = const FileMode(0);
@@ skipping 170 matching lines @@
    * The [errorHandler] is called if the operation fails.
    */
   void readAsBytes();
 
   /**
    * Synchronously read the entire file contents as a list of bytes.
    */
   List<int> readAsBytesSync();
 
   /**
-   * Read the entire file contents as text using the give [encoding]
+   * Read the entire file contents as text using the given [encoding]
    * ('UTF-8', 'ISO-8859-1', 'ASCII'). By default the encoding is
    * 'UTF-8'.
    *
    * When the operation completes the [readAsTextHandler] is called
    * with the resulting string.  The [errorHandler] is called if the
    * operation fails.
    */
   void readAsText([String encoding]);
 
   /**
    * Synchronously read the entire file contents as text using the
-   * give [encoding] ('UTF-8', 'ISO-8859-1', 'ASCII'). By default the
+   * given [encoding] ('UTF-8', 'ISO-8859-1', 'ASCII'). By default the
    * encoding is 'UTF-8'.
    */
   String readAsTextSync([String encoding]);
 
   /**
    * Read the entire file contents as lines of text using the give
    * [encoding] ('UTF-8', 'ISO-8859-1', 'ASCII'). By default the
    * encoding is 'UTF-8'.
    *
    * When the operation completes the [readAsLinesHandler] is called
    * with the resulting string.  The [errorHandler] is called if the
    * operation fails.
    */
   void readAsLines();
 
   /**
    * Synchronously read the entire file contents as lines of text
-   * using the give [encoding] ('UTF-8', 'ISO-8859-1', 'ASCII'). By
+   * using the given [encoding] ('UTF-8', 'ISO-8859-1', 'ASCII'). By
    * default the encoding is 'UTF-8'.
    */
   List<String> readAsLinesSync([String encoding]);
 
   /**
    * Get the name of the file.
    */
   String get name();
 
   /**
@@ skipping 272 matching lines @@
    */
   void set errorHandler(void handler(String error));
 }
 
 
 class FileIOException implements Exception {
   const FileIOException([String this.message = ""]);
   String toString() => "FileIOException: $message";
   final String message;
 }