Fix a couple of doc comment references - and many spelling mistakes

sdk/lib/io/stdio.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;
 
 const int _STDIO_HANDLE_TYPE_TERMINAL = 0;
 const int _STDIO_HANDLE_TYPE_PIPE = 1;
 const int _STDIO_HANDLE_TYPE_FILE = 2;
 const int _STDIO_HANDLE_TYPE_SOCKET = 3;
@@ skipping 136 matching lines @@
     * with some terminals supporting more escape sequences than others,
     * and some terminals even differing in behavior for the same escape
     * sequence.
     *
     * The ANSI color selection is generally supported.
     *
     * Currently, a `TERM` environment variable containing the string `xterm`
     * will be taken as evidence that ANSI escape sequences are supported.
     * On Windows, only versions of Windows 10 after v.1511
     * ("TH2", OS build 10586) will be detected as supporting the output of
-    * ANSI escape sequences, and only versions after v.1607 ("Anniversery
+    * ANSI escape sequences, and only versions after v.1607 ("Anniversary
     * Update", OS build 14393) will be detected as supporting the input of
     * ANSI escape sequences.
     */
   external bool get supportsAnsiEscapes;
 
   /**
    * Synchronously read a byte from stdin. This call will block until a byte is
    * available.
    *
    * If at end of file, -1 is returned.
@@ skipping 53 matching lines @@
     * with some terminals supporting more escape sequences than others,
     * and some terminals even differing in behavior for the same escape
     * sequence.
     *
     * The ANSI color selection is generally supported.
     *
     * Currently, a `TERM` environment variable containing the string `xterm`
     * will be taken as evidence that ANSI escape sequences are supported.
     * On Windows, only versions of Windows 10 after v.1511
     * ("TH2", OS build 10586) will be detected as supporting the output of
-    * ANSI escape sequences, and only versions after v.1607 ("Anniversery
+    * ANSI escape sequences, and only versions after v.1607 ("Anniversary
     * Update", OS build 14393) will be detected as supporting the input of
     * ANSI escape sequences.
     */
   bool get supportsAnsiEscapes => _supportsAnsiEscapes(_fd);
 
   external bool _hasTerminal(int fd);
   external int _terminalColumns(int fd);
   external int _terminalLines(int fd);
   external static bool _supportsAnsiEscapes(int fd);
 
@@ skipping 180 matching lines @@
 }
 
 class _StdIOUtils {
   external static _getStdioOutputStream(int fd);
   external static Stdin _getStdioInputStream();
 
   /// Returns the socket type or `null` if [socket] is not a builtin socket.
   external static int _socketType(Socket socket);
   external static _getStdioHandleType(int fd);
 }