icon cache scriplet guideline update

[Jason L Tibbitts III]

>>>>> "MC" == Matthias Clasen <mclasen at redhat.com> writes:

MC> It is interesting to note that this proposal doesn't actually
MC> address the one problem that there is with the current snipplets,
MC> namely that we keep regenerating the cache over and over.

Well, the xdg script could do that.  We certainly shouldn't push such
logic into the scriptlets of every package.

 - J<