big update to observe, template_binding, polymer

pkg/observe/lib/src/list_diff.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.
 
 library observe.src.list_diff;
 
 import 'dart:math' as math;
 import 'dart:collection' show UnmodifiableListView;
 
 /**
@@ skipping 363 matching lines @@
  *     model.insertAll(0, ['c', 'd', 'e']);
  *     model.removeRange(1, 3);
  *     model.insert(1, 'f');
  *
  * Here, we inserted some records and then removed some of them.
  * If someone processed these records naively, they would "play back" the
  * insert incorrectly, because those items will be shifted.
  */
 List<ListChangeRecord> projectListSplices(List list,
     List<ListChangeRecord> records) {
-  if (records.length == 1) return records;
+  if (records.length <= 1) return records;
 
   var splices = [];
   for (var splice in _createInitialSplices(list, records)) {
     if (splice.addedCount == 1 && splice.removed.length == 1) {
       if (splice.removed[0] != list[splice.index]) splices.add(splice);
       continue;
     }
 
     splices.addAll(calcSplices(list, splice.index,
         splice.index + splice.addedCount, splice._removed, 0,
         splice.removed.length));
   }
 
   return splices;
 }