Big merge from experimental to bleeding edge.

utils/pub/yaml/yaml.dart

Index: utils/pub/yaml/yaml.dart
diff --git a/utils/pub/yaml/yaml.dart b/utils/pub/yaml/yaml.dart
index 11984c34d5fe298ea1a375c1f40eabbb5fa90877..6ce890ccf95920b5789e68430d36e484df091af2 100644
--- a/utils/pub/yaml/yaml.dart
+++ b/utils/pub/yaml/yaml.dart
@@ -39,8 +39,9 @@ loadYaml(String yaml) {
 /// are YamlMaps. These have a few small behavioral differences from the default
 /// Map implementation; for details, see the YamlMap class.
 List loadYamlStream(String yaml) {
-  return new _Parser(yaml).l_yamlStream().map((doc) =>
-      new _Constructor(new _Composer(doc).compose()).construct());
+  return new _Parser(yaml).l_yamlStream().mappedBy((doc) =>
+      new _Constructor(new _Composer(doc).compose()).construct())
+      .toList();
 }
 
 /// An error thrown by the YAML processor.