GMP 6.1.0 release candidate available

[paul zimmermann]

       Dear Marco,

> A release candidate for GMP 6.1.0 is available for download here:
> If no problems arise, we plan to release GMP 6.1.0 next Wednesday.

this is a short time for users to give feedback!

I was able to compile and run the test suites of GMP-ECM, MPFR and CADO-NFS.

A few comments:

* mini-gmp.c still does not provide gmp_version

* mini-gmp.h still does not provide __GNU_MP_VERSION, __GNU_MP_VERSION_MINOR,
  __GNU_MP_VERSION_PATCHLEVEL, gmp_randstate_t and GMP_NUMB_BITS

* mpz_div_2exp would be welcome in mini-gmp too

Paul