[Groff] [UTP] Updated UTP macros and documentation

[Jon Snader]

I've just sent Larry an updated set of UTP macros and their documentation.
I added the following:
        H, HI, and HB macros for Helvetica
        The X[1-4] macros by Heinz-Jürgen Oertel for virtual screens
        The utp macro now explicitly set ps/vs (and PS/VS) to 10/12

Give Larry a little time to get them added to his site.  I'm sure he'll
post when he gets them up.

Jon Snader

P.S.  Soon I'll add the notes facility as requested by Michael Hobgood.
If anyone else needs something, please let me know via the list.