Update project authors statements to Dartino

pkg/immi_samples/lib/drawer.immi

-// Copyright (c) 2015, the Fletch project authors. Please see the AUTHORS file
+// Copyright (c) 2015, the Dartino 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.md file.
 
 // TODO(zerny): Support disjoint unions and syntax for optional values?
 node EmptyPane {}
 
 node Drawer {
   Node left;
   Node center;
   Node right;
 
   bool leftVisible;
   bool rightVisible;
 
   void toggleLeft();
   void toggleRight();
 }