Put data into jgroff. 
Issue: don't install everything, but link redundant stuff from 
/usr/share/groff ?
$OpenBSD: patch-Makefile_in,v 1.1.1.1 2000/04/12 20:34:11 espie Exp $
--- Makefile.in.orig	Tue Apr 11 23:43:40 2000
+++ Makefile.in	Tue Apr 11 23:44:42 2000
@@ -75,7 +75,7 @@ bindir=$(exec_prefix)/bin
 
 # datasubdir says where to install data files
 datadir=$(prefix)/share
-datasubdir=$(datadir)/groff
+datasubdir=$(datadir)/jgroff
 
 # fontdir says where to install dev*/*.
 fontdir=$(datasubdir)/font