German sharp S uppercase mapping

[Mark E. Shoulson]

I remember when the debate about adding ẞ was ongoing here on this 
list.  There were lots of old fonts shown which had a distinct uppercase 
ß.  I remember that some insisted there was no such letter, pointing to 
the pronouncements of the then-current Große Duden, which said that ß 
capitalizes to SS, and yet the cover of *that very book*, in all-capital 
letters an inch high, clearly showed its title as DER GROẞE DUDEN.

We can find the discussion in the list archives somewhere. Suffice to 
say, ẞ does seem to be a real thing and seems to have been so even 
before it was recognized.

~mark