Update project authors statements to Dartino

lib/core/bigint.dart

-// 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.
 
 // Copyright (c) 2014, 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.
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
@@ skipping 2152 matching lines @@
 
   int _mul(_Uint32Digits x_digits, int x_used,
            _Uint32Digits y_digits, int y_used,
            _Uint32Digits r_digits) {
     var r_used = _Bigint._mulDigits(x_digits, x_used,
                                     y_digits, y_used,
                                     r_digits);
     return _reduce(r_digits, r_used);
   }
 }