Since there is only one Tk class like this, a fancy macro might not have
much value. What we need is a bunch of:

(defobserver title$ ((self window))
   (tk-format '(:configure "title") "wm title . ~a" (or new-value
"Untitled")))

...observers, one per "wm XXXX...." that might follow from a window
attribute. Note that, unlike intervening during i-i, this works even on
/changes/ to the title (which would be unusual, but for other window
attributes perfectly normal. so let's hand;e the general case...

Anyway, if someone wants to code up the observers...