I submitted a proposal for user-redefinable printf, but it was not approved,
because it was not really a proposal, just a "does this look cool".  ;)

I've done some research on this; the way that Thompson did it, which is
basically correct, is to distinguish between "format" and "modifier"
characters.

	%lu
is a modifier followed by a format.  Perhaps we should use things lke
	%Sd
	%Od
for size_t and off_t?

(We can; they're implementation space, not ANSI space.)

-s