[Groff] migration

[mcclosk]

Thank you all very much indeed for your speedy and helpful replies. 

The suggestion about dierisis and macron accents works (of course),
and I've passed on the suggestion about using the code in tmac.s
instead. 

I've also downloaded the latest version of groff from the GNU archive
and will install it later today. Hopefully, that will fix the problem
with compatibility mode. I'll report back here if it doesn't. 

This was very impressive indeed. I'll encourage the authoress to
subscribe to the list.

Thanks,

Jim McCloskey