use new license

banner.txt

@@ -0,0 +1,9 @@
+/**
+ * @license
+ * Copyright (c) 2014 The Polymer Project Authors. All rights reserved.
+ * This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
+ * The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
+ * The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
+ * Code distributed by Google as part of the polymer project is also
+ * subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
+ */

gruntfile.js

@@ -29,7 +29,7 @@ module.exports = function(grunt) {
           sourceMap: true,
           sourceMapName: 'build/polymer.js.map',
           sourceMapIncludeSources: true,
-          banner: grunt.file.read('LICENSE') + '// @version: <%= buildversion %>'
+          banner: grunt.file.read('banner.txt') + '// @version: <%= buildversion %>'
           //mangle: false, beautify: true, compress: false
         },
         files: {