(ssh_dss_public_key): Obsoleted by the SIGNER_GET_VERIFIER and
PUBLIC_KEY methods.
(parse_ssh_dss_public): Renamed (was parse_dsa_public), and
changed the return type.
(make_dsa_verifier_internal): New method used by make_dsa_verifier
and make_dsa_signer.
(dsa_signer): Added pointer to a corresponding verifier object.
Replaces the dsa_public struct.
Also deleted some old code.

Rev: src/dsa.c:1.23