Some fixes to work better with the services framework

pkg/serialization/lib/serialization.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.
 
 /**
  * This provides a general-purpose serialization facility for Dart objects. A
  * [Serialization] is defined in terms of [SerializationRule]s and supports
  * reading and writing to different formats.
  *
  * Setup
@@ skipping 333 matching lines @@
 
   /**
    * Read the serialized data from [input] and return the root object
    * from the result. If there are objects that need to be resolved
    * in the current context, they should be provided in [externals] as a
    * Map from names to values. In particular, in the current implementation
    * any class mirrors needed should be provided in [externals] using the
    * class name as a key. In addition to the [externals] map provided here,
    * values will be looked up in the [externalObjects] map.
    */
-  read(String input, [Map externals = const {}]) {
+  read(input, [Map externals = const {}]) {

[justinfagnani, 2013/02/09 21:21:56]

now that the type annotation is removed, can you document what types are allowed
for input?

[Alan Knight, 2013/02/11 23:38:42]

Done. Also fixed up the main doc comment some.

     return newReader().read(input, externals);
   }
 
   /**
    * Return a new [Reader] object for this serialization. This is useful if
    * you want to do something more complex with the reader than just returning
    * the final result.
    */
   Reader newReader([Format format]) => new Reader(this, format);
 
@@ skipping 95 matching lines @@
 }
 
 /**
  * An exception class for errors during serialization.
  */
 class SerializationException implements Exception {
   final String message;
   const SerializationException([this.message]);
   toString() => "SerializationException($message)";
 }