New code for primality testing

[paul zimmermann]

> > Some other free software projects already contain code for primality
> > proving. E.g. Pari/GP [http://pari.math.u-bordeaux.fr/] implement both
> > APR-CL and ECPP... I don't think GMP should duplicate that (good) work.
> 
> mpz_aprcl uses mpz already and is on a similar track about license
> https://sourceforge.net/projects/mpzaprcl/
> 
> Thank you for the pointers on these projects.
> It's just that, personal feeling maybe, there is a something "missing" from
> the absence of deterministic primality test function (whatever the perf, to some extent).
> But if it's too complex it's indeed a good reason.

GMP-ECM contains an implementation of APRCL, written by David Cleaver.
See aprtcle/mpz_aprcl.c.

Paul