Remove generated directories with 100s of files.

client/html/generated/html/interface/HTMLOptionsCollection.dart

Index: client/html/generated/html/interface/HTMLOptionsCollection.dart
diff --git a/client/html/generated/html/interface/HTMLOptionsCollection.dart b/client/html/generated/html/interface/HTMLOptionsCollection.dart
deleted file mode 100644
index f1bd78838c92adb2f380d5c97284bc3ec09e6f39..0000000000000000000000000000000000000000
--- a/client/html/generated/html/interface/HTMLOptionsCollection.dart
+++ /dev/null
@@ -1,14 +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 HTMLOptionsCollection extends HTMLCollection {
-
-  int length;
-
-  int selectedIndex;
-
-  void remove(int index);
-}