[Orgmode] [c]ompute property value ?

[Bastien]

Hi Carsten,

by pressing the C-c C-c in front of :PROPERTIES:, i've been offered
these property actions:

  Property Action:  [s]et  [d]elete  [D]delete globally

(Should be "[D]elete", no?)

It might be useful here to be able to [c]ompute or [u]pdate the property
value depending on its children, at least for values with a summary type
like {+}, {X} or {:}.  

Perhaps [C]ompute/[U]pdate globally (all properties) has also its place
here.

-- 
Bastien