The makefiles don't really allow for a proto-area-style install; this
tweak, plus the bits in files/solaris, let this happen correctly.
--- sys/unix/Makefile.top 2015-11-18 12:54:59.000000000 -0800
+++ sys/unix/Makefile.top 2016-04-14 16:37:08.807692850 -0700
@@ -206,7 +206,7 @@
cp util/recover $(INSTDIR)
-if test -n '$(SHELLDIR)'; then rm -f $(SHELLDIR)/$(GAME); fi
if test -n '$(SHELLDIR)'; then \
- sed -e 's;/usr/games/lib/nethackdir;$(HACKDIR);' \
+ sed -e 's;/usr/games/lib/nethackdir;$(CLIENT_HACKDIR);' \
-e 's;HACKDIR/nethack;HACKDIR/$(GAME);' \
> $(SHELLDIR)/$(GAME) ; fi