Antinews for Unicode stuff

[Chong Yidong]

I started writing the Emacs 23 Antinews, and got stuck on the internal
encoding entry (i.e., the entry that describes the move from Unicode in
Emacs 23 to emacs-mule in Emacs 22 for someone living backwards in
time).

Could someone please take a stab at this?  It's not absolutely necessary
for the entry to be funny---we are mostly trying to convey information
here.