New winetricks: msxml6, riched30

[Dan Kegel]

Johan Dahlin sent in a patch to add msxml6, and said
"It's enough to make msi2xml.exe to at least start-up (before failing in msi
later)."

Tom Wickline some time ago sent in a suggestion for
adding riched30.  I didn't know any apps it helped, but
apparantly Novell thinks it helps Groupwise a bit.
So it's in now.  Caution, it doesn't update riched32, no idea
what happens if apps try to use it after this...

As always, it's available at
  http://kegel.com/wine/winetricks
and the svn repository is
  http://code.google.com/p/winezeug/