Big merge from experimental to bleeding edge.

samples/markdown/markdown.dart

Index: samples/markdown/markdown.dart
diff --git a/samples/markdown/markdown.dart b/samples/markdown/markdown.dart
index e7d502730d0c68e76228cead2231c7f91ee37bb8..6eff567681e4fce58d0682bb40f470596588e57c 100644
--- a/samples/markdown/markdown.dart
+++ b/samples/markdown/markdown.dart
@@ -33,7 +33,7 @@ main() {
 String readFile(String path) {
   final file = (new File(path)).openSync();
   final length = file.lengthSync();
-  final buffer = new List<int>(length);
+  final buffer = new List<int>.fixedLength(length);
   final bytes = file.readListSync(buffer, 0, length);
   file.closeSync();
   return new String.fromCharCodes(buffer);