[Orgmode] Use of display properties as a caching mechanism

[Nicolas Girard]

When hacking the org-icons stuff, I came to realize that emacs allows
to attach any set or property/value to any part of a buffer.

It seems to me like org-mode could perfectly use this as a caching mechanism.
What bout storing time-expensive informations as special properties
attached to the first '*' of a heading ?
The price to pay would be to enforce the consistency of this cache --
as with any cache, after all; as a benefit, this may boost org-mode's
performances.
What do you think ?

Nicolas