<ndbm.h> missing
database.c won't compile because <ndbm.h> is missing. On my system
(Debian potato), <ndbm.h> is in fact <db1/ndbm.h>. As a kludge, I've
modified my copy of database.c, but I'm sure it's not the right fix.
I understand too little of what's going on in database.c to provide a
good fix, though.