Remove .writeStream, .consume and rewrite IOSink to correctly implement a (sane) well-defined behav…

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;
 
 /**
  * FileMode describes the modes in which a file can be opened.
  */
 class FileMode {
@@ skipping 187 matching lines @@
    *
    * * [FileMode.WRITE]: truncates the file to length zero.
    * * [FileMode.APPEND]: sets the initial write position to the end
    *   of the file.
    *
    *  When writing strings through the returned [IOSink] the encoding
    *  specified using [encoding] will be used. The returned [IOSink]
    *  has an [:encoding:] property which can be changed after the
    *  [IOSink] has been created.
    */
-  IOSink<File> openWrite({FileMode mode: FileMode.WRITE,
-                          Encoding encoding: Encoding.UTF_8});
+  IOSink openWrite({FileMode mode: FileMode.WRITE,
+                    Encoding encoding: Encoding.UTF_8});
 
   /**
    * Read the entire file contents as a list of bytes. Returns a
    * [:Future<List<int>>:] that completes with the list of bytes that
    * is the contents of the file.
    */
   Future<List<int>> readAsBytes();
 
   /**
    * Synchronously read the entire file contents as a list of bytes.
@@ skipping 305 matching lines @@
         sb.write(" ($osError)");
       }
     } else if (osError != null) {
       sb.write(": osError");
     }
     return sb.toString();
   }
   final String message;
   final OSError osError;
 }