New undo element (fun . args)

[Kim F. Storm]

I appreciate the new undo element (fun . args), but there are
two problems with the specific format chosen:

1) it does not work with the "undo-in-region" funtionality.

2) AFAICS, it effectively blocks any future extensions to the
   undo list format.

To fix both of these problems, I suggest to change the format to:

   (apply FUN ARGS BEG . END)

and fix the undo in region to understand it.

-- 
Kim F. Storm  http://www.cua.dk