Fix some markdown issues in library docs (related to https://github.com/dart-lang/dartdoc/issues/96…

sdk/lib/io/file_system_entity.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 type of an entity on the file system, such as a file, directory, or link.
  *
  * These constants are used by the [FileSystemEntity] class
@@ skipping 464 matching lines @@
       return response;
     });
   }
 
   static final RegExp _absoluteWindowsPathPattern =
       new RegExp(r'^(\\\\|[a-zA-Z]:[/\\])');
 
   /**
    * Returns a [bool] indicating whether this object's path is absolute.
    *
-   * On Windows, a path is absolute if it starts with \\ or a drive letter
-   * between a and z (upper or lower case) followed by :\ or :/.
+   * On Windows, a path is absolute if it starts with \\\\ or a drive letter
+   * between a and z (upper or lower case) followed by :\\ or :/.
    * On non-Windows, a path is absolute if it starts with /.
    */
   bool get isAbsolute {
     if (Platform.isWindows) {
       return path.startsWith(_absoluteWindowsPathPattern);
     } else {
       return path.startsWith('/');
     }
   }
 
@@ skipping 120 matching lines @@
   external static _resolveSymbolicLinks(String path);
 
   // Finds the next-to-last component when dividing at path separators.
   static final RegExp _parentRegExp = Platform.isWindows ?
      new RegExp(r'[^/\\][/\\]+[^/\\]') :
      new RegExp(r'[^/]/+[^/]');
 
   /**
    * Removes the final path component of a path, using the platform's
    * path separator to split the path.  Will not remove the root component
-   * of a Windows path, like "C:\" or "\\server_name\".
+   * of a Windows path, like "C:\\" or "\\\\server_name\\".
    * Ignores trailing path separators, and leaves no trailing path separators.
    */
   static String parentOf(String path) {
     int rootEnd = -1;
     if (Platform.isWindows) {
       if (path.startsWith(_absoluteWindowsPathPattern)) {
         // Root ends at first / or \ after the first two characters.
         rootEnd = path.indexOf(new RegExp(r'[/\\]'), 2);
         if (rootEnd == -1) return path;
       } else if (path.startsWith('\\') || path.startsWith('/')) {
@@ skipping 194 matching lines @@
     return buffer.toString();
   }
 }
 
 
 class _FileSystemWatcher {
   external static Stream<FileSystemEvent> _watch(
       String path, int events, bool recursive);
   external static bool get isSupported;
 }