Rearranges the polymer package now that the old compiler is gone.

pkg/polymer/lib/src/build/script_compactor.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.
 
 /** Transfomer that combines multiple dart script tags into a single one. */
-library polymer.src.transform.script_compactor;
+library polymer.src.build.script_compactor;
 
 import 'dart:async';
 
 import 'package:barback/barback.dart';
 import 'package:html5lib/parser.dart' show parseFragment;
 import 'package:path/path.dart' as path;
 
 import 'code_extractor.dart'; // import just for documentation.
 import 'common.dart';
 
@@ skipping 102 matching lines @@
 
 void main() {
   initPolymer([
 """;
 
 // TODO(sigmund): investigate alternative to get the baseUri (dartbug.com/12612)
 const _mainSuffix = """
     ], currentMirrorSystem().isolate.rootLibrary.uri.toString());
 }
 """;