I think the remaining items on http://www.lysator.liu.se/~nisse/nettle/plan.html aren't very urgent, and can be postponed.
Discussed recently, but not on that list, is mem_equalp (or whatever it should be called). That's also not very urgent.
I plan to move NETTLE_USE_MINI_GMP from bignum.h to version.h, and drop bignum.h.in. It should be enough with one configure-generated header like that. It also has the advantage that version.h actually gets used during the build. That change touches a couple of files, so I don't want to check that in tonight.
Anyway, I think it's time to get into final testing. I've done some tests on freebsd, revealing one real bug (triggered only when compiled with the ancient gcc version freebsd keeps in /usr/bin). And I've made some fixes to what gets included by make dist.
I hope to be able to create a nettle-3.1rc1.tar.gz in a day or two.
Regards, /Niels