Make new StreamController be async by default.

Change all instances, except some tests, to be sync still.
Rename Multiplex to Broadcast everywhere.

R=floitsch@google.com

Review URL: https://codereview.chromium.org//16125005

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/logging@23453 260f80e4-7a28-3924-810f-c04153c831b5
diff --git a/lib/logging.dart b/lib/logging.dart
index 94bf5f3..b29f076 100644
--- a/lib/logging.dart
+++ b/lib/logging.dart
@@ -196,7 +196,7 @@
   Stream<LogRecord> _getStream() {
     if (hierarchicalLoggingEnabled || parent == null) {
       if (_controller == null) {
-        _controller = new StreamController<LogRecord>();
+        _controller = new StreamController<LogRecord>(sync: true);
         _stream = _controller.stream.asBroadcastStream();
       }
       return _stream;