21.5 Mule UTF use un-define (Mule-Ucs)

[Stephen J. Turnbull]

Uwe Brauer writes:

 > Well, uh, I compiled and installed xemacs-21.5 and then the sumo and
 > sumo-mule packages and ups Mule-UCS was there! 

The whole point of the packages is that they are distributed
independently of the version of the core.  It makes no sense to
proliferate SUMOs simply to distinguish *one* package (Mule-UCS is the
only package that has different usage for 21.4 and 21.5).

I suppose we could remove Mule-UCS from the SUMOs entirely and make
21.4 users download it separately, but it was added around the time
that 21.1 was released so it's in the SUMO for historical reasons.