Fix Directory, File and Link constructor text.

sdk/lib/io/directory.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.
 
 part of dart.io;
 
 /**
  * A reference to a directory (or _folder_) on the file system.
  *
  * A Directory instance is an object holding a [path] on which operations can
@@ skipping 100 matching lines @@
  * a tutorial about writing command-line apps, includes information
  * about files and directories.
  */
 abstract class Directory extends FileSystemEntity {
   /**
    * Gets the path of this directory.
    */
   final String path;
 
   /**
-   * Creates a directory object. The path is either an absolute path,
-   * or it is a relative path which is interpreted relative to the directory
-   * in which the Dart VM was started.
+   * Creates a [Directory] object.
+   *
+   * If [path] is a relative path, it will be interpreted relative to the
+   * current working directory (see [Directory.current]), when used.
+   *
+   * If [path] is an absolute path, it will be immune to changes to the
+   * current working directory.
    */
   factory Directory(String path) => new _Directory(path);
 
   /**
    * Create a Directory object from a URI.
    *
    * If [uri] cannot reference a directory this throws [UnsupportedError].
    */
   factory Directory.fromUri(Uri uri) => new Directory(uri.toFilePath());
 
@@ skipping 157 matching lines @@
    * directories, files, and links.
    */
   List<FileSystemEntity> listSync({bool recursive: false,
                                    bool followLinks: true});
 
   /**
    * Returns a human readable string for this Directory instance.
    */
   String toString();
 }