Cascading cookie counts

[George Mauer]

* Cascading Checkbox Cookie Counts
  I would like checkbox cookies to show the total of all cookies beneath them regardless of hierarchy nesting.
  The code for ~org-update-checkbox-count~ is more complex than I expected so before spending time digging into this, maybe someone here has a tip?
 
** This should show 3/5 [1/2]
   - [X] Done
   - [ ] Not Done
** Nesting level 1
   - [ ] Not Done
   - [X] Done
** Nesting level 2
*** Nesting level 2.1
    - [X] Done
     
** Cookie data recursive doesn't seem to affect this
   My understanding is that there's a cookie data ~<recursive>~ property flag you can use. I assumed that's what this was for but it seems to not affect things (I've tried both with and without the angle braces, but the regex seems to imply braces which is odd)
*** This should show 3/5 [1/2]
    :PROPERTIES:
    :COOKIE_DATA: <recursive>
    :END:
    - [X] Done
    - [ ] Not Done
*** Nesting level 1
    - [ ] Not Done
    - [X] Done
*** Nesting level 2
**** Nesting level 2.1
     - [X] Done