pubkey: Move sexp parsing for gcry_pk_sign to the modules.
* cipher/rsa.c (rsa_sign): Revamp. * cipher/dsa.c (dsa_sign): Revamp. * cipher/elgamal.c (elg_sign): Revamp. * cipher/ecc.c (ecc_sign): Revamp. * cipher/pubkey.c (gcry_pk_sign): Simplify.
- Signed-off-by: Werner Koch <wk@gnupg.org>