* cipher/ecc-misc.c (_gcry_ecc_compute_public): Add optional args G
and d.  Change all callers.
* cipher/ecc.c (gen_y_2): Remove.
(check_secret_key): Use generic public key compute function.  Adjust
for use with Ed25519 and EdDSA.
(nist_generate_key): Do not use the compliant key thingy for Ed25519.
(ecc_check_secret_key): Make parameter parsing similar to the other
functions.
* cipher/ecc-curves.c (domain_parms): Zero prefix some parameters so
that _gcry_ecc_update_curve_param works correctly.
* tests/keygen.c (check_ecc_keys): Add "param" flag.  Check all
Ed25519 keys.