New winetricks: added riched20

[Dan Kegel]

Seeing as we have about 45 open riched20 bugs,
and some recent regressions, I figured it'd be
useful to add riched20 to winetricks.

Incidentally, since I lost the workstation that had
the old rcs repository it was in, I gave in to modern
times and put it in a new repository at
  http://code.google.com/p/winezeug/
- Dan

p.s. I have a backlog of two or three big updates,
one from Lei for codecs, and another from
Andrea Bocci for all sorts of things.
I'd merge them now but I have to go read another
Discworld book... they're like crack...