Remove generated directories with 100s of files.

client/html/generated/html/frog/ButtonElement.dart

Index: client/html/generated/html/frog/ButtonElement.dart
diff --git a/client/html/generated/html/frog/ButtonElement.dart b/client/html/generated/html/frog/ButtonElement.dart
deleted file mode 100644
index 8eb97739b8a63d74ef43ddf0d099a40a14ab832e..0000000000000000000000000000000000000000
--- a/client/html/generated/html/frog/ButtonElement.dart
+++ /dev/null
@@ -1,37 +0,0 @@
-
-class _ButtonElementImpl extends _ElementImpl implements ButtonElement native "*HTMLButtonElement" {
-
-  bool autofocus;
-
-  bool disabled;
-
-  final _FormElementImpl form;
-
-  String formAction;
-
-  String formEnctype;
-
-  String formMethod;
-
-  bool formNoValidate;
-
-  String formTarget;
-
-  final _NodeListImpl labels;
-
-  String name;
-
-  final String type;
-
-  final String validationMessage;
-
-  final _ValidityStateImpl validity;
-
-  String value;
-
-  final bool willValidate;
-
-  bool checkValidity() native;
-
-  void setCustomValidity(String error) native;
-}