Fix some bad documentation links.

sdk/lib/io/file.dart

 // Copyright (c) 2013, 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.
 
 part of dart.io;
 
 /**
  * The modes in which a File can be opened.
  */
 class FileMode {
@@ skipping 142 matching lines @@
  *
  *     void main() {
  *       final filename = 'file.txt';
  *       new File(filename).writeAsString('some content')
  *         .then((File file) {
  *           // Do something with the file.
  *         });
  *     }
  *
  * You can also write to a file using a [Stream]. Open the file with
- * [openWrite], which returns a stream to which you can write data.
- * Be sure to close the file with the [close] method.
+ * [openWrite], which returns an [IOSink] to which you can write data.
+ * Be sure to close the sink with the [IOSink.close] method.
  *
  *     import 'dart:io';
  *
  *     void main() {
  *       var file = new File('file.txt');
  *       var sink = file.openWrite();
  *       sink.write('FILE ACCESSED ${new DateTime.now()}\n');
  *
  *       // Close the IOSink to free system resources.
  *       sink.close();
@@ skipping 161 matching lines @@
  * if the information is available. Blocks until the information can be returned
  * or it is determined that the information is not available.
  *
  * Throws a [FileSystemException] if the operation fails.
  */
   DateTime lastAccessedSync();
 
   /**
    * Modifies the time the file was last accessed.
    *
-   * Throws a [FilsSystemException] if the time cannot be set.
+   * Throws a [FileSystemException] if the time cannot be set.
    */
   Future setLastAccessed(DateTime time);
 
   /**
    * Synchronously modifies the time the file was last accessed.
    *
-   * Throws a [FilsSystemException] if the time cannot be set.
+   * Throws a [FileSystemException] if the time cannot be set.
    */
   void setLastAccessedSync(DateTime time);
 
 /**
  * Get the last-modified time of the file.
  *
  * Returns the date and time when the file was last modified, if the
  * information is available.
  *
  * Throws a [FileSystemException] if the operation fails.
  */
   Future<DateTime> lastModified();
 
 /**
  * Get the last-modified time of the file.
  *
  * Returns the date and time when the file was last modified,
  * if the information is available. Blocks until the information can be returned
  * or it is determined that the information is not available.
  *
  * Throws a [FileSystemException] if the operation fails.
  */
   DateTime lastModifiedSync();
 
   /**
    * Modifies the time the file was last modified.
    *
-   * Throws a [FilsSystemException] if the time cannot be set.
+   * Throws a [FileSystemException] if the time cannot be set.
    */
   Future setLastModified(DateTime time);
 
   /**
    * Synchronously modifies the time the file was last modified.
    *
    * If the attributes cannot be set, throws a [FileSystemException].
    */
   void setLastModifiedSync(DateTime time);
 
@@ skipping 557 matching lines @@
       sb.write(": $osError");
       if (path != null) {
         sb.write(", path = '$path'");
       }
     } else if (path != null) {
       sb.write(": $path");
     }
     return sb.toString();
   }
 }