Add close to input stream and cleanup socket and streams

runtime/bin/file.dart

 // Copyright (c) 2011, 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.
 
 interface File default _File {
   /**
    * Create a File object.
    */
   File(String name);
 
@@ skipping 62 matching lines @@
   /**
    * Synchronously get the canonical full path corresponding to the file name.
    */
   String fullPathSync();
 
   /**
    * Create a new independent input stream for the file. The file
    * input stream must be closed when no longer used to free up
    * system resources.
    */
-  FileInputStream openInputStream();
+  InputStream openInputStream();
 
   /**
    * Creates a new independent output stream for the file. The file
    * output stream must be closed when no longer used to free up
    * system resources.
    */
-  FileOutputStream openOutputStream();
+  OutputStream openOutputStream();
 
   /**
    * Get the name of the file.
    */
   String get name();
 
   // Event handlers.
   void set existsHandler(void handler(bool exists));
   void set createHandler(void handler());
   void set deleteHandler(void handler());
@@ skipping 146 matching lines @@
   void set noPendingWriteHandler(void handler());
   void set positionHandler(void handler(int position));
   void set setPositionHandler(void handler());
   void set truncateHandler(void handler());
   void set lengthHandler(void handler(int length));
   void set flushHandler(void handler());
   void set errorHandler(void handler(String error));
 }
 
 
-interface FileInputStream extends InputStream {
-  void close();
-}
-
-
-interface FileOutputStream extends OutputStream {
-}
-
-
 class FileIOException implements Exception {
   const FileIOException([String this.message = ""]);
   String toString() => "FileIOException: $message";
   final String message;
 }