Roll Observatory packages and add a roll script

packages/analyzer/example/scanner_driver.dart

+#!/usr/bin/env 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.
+
+import 'dart:io';
+
+import 'package:analyzer/src/generated/scanner.dart';
+
+main(List<String> args) {
+  print('working dir ${new File('.').resolveSymbolicLinksSync()}');
+
+  if (args.length == 0) {
+    print('Usage: scanner_driver [files_to_scan]');
+    exit(0);
+  }
+
+  for (var arg in args) {
+    _scan(new File(arg));
+  }
+}
+
+_scan(File file) {
+  var src = file.readAsStringSync();
+  var reader = new CharSequenceReader(src);
+  var scanner = new Scanner(null, reader, null);
+  var token = scanner.tokenize();
+  while (token.type != TokenType.EOF) {
+    print(token);
+    token = token.next;
+  }
+}