* lisp/org-archive.el (org-archive-subtree): Update todo statistics
when calling `org-archive-subtree'.
(org-archive-to-archive-sibling): Update cookie statistics when
calling `org-archive-to-archive-sibling'.
* testing/lisp/test-org-archive.el: New file.
This can be disabled by setting `org-provide-todo-statistics' to nil.
Jay Kamat