Remove generated directories with 100s of files.

client/html/generated/html/interface/ButtonElement.dart

Index: client/html/generated/html/interface/ButtonElement.dart
diff --git a/client/html/generated/html/interface/ButtonElement.dart b/client/html/generated/html/interface/ButtonElement.dart
deleted file mode 100644
index d86e0f75427600f30c4a742f16060b301a4f7e54..0000000000000000000000000000000000000000
--- a/client/html/generated/html/interface/ButtonElement.dart
+++ /dev/null
@@ -1,42 +0,0 @@
-// Copyright (c) 2012, 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.
-
-// WARNING: Do not edit - generated code.
-
-interface ButtonElement extends Element {
-
-  bool autofocus;
-
-  bool disabled;
-
-  final FormElement form;
-
-  String formAction;
-
-  String formEnctype;
-
-  String formMethod;
-
-  bool formNoValidate;
-
-  String formTarget;
-
-  final NodeList labels;
-
-  String name;
-
-  final String type;
-
-  final String validationMessage;
-
-  final ValidityState validity;
-
-  String value;
-
-  final bool willValidate;
-
-  bool checkValidity();
-
-  void setCustomValidity(String error);
-}