* client.c (handle_openpgp_signatures): Rename to...

(handle_openpgp_signature): ...this and handle OpenPGP-signature
responses as documented.
(client_write_sigfile): Ditto on the response handling.
(responses): Rename OpenPGP-signatures to OpenPGP-signature.  Handle
new function name.
* rcs.c (iRCS_get_openpgp_signatures): New function factored from...
(RCS_get_openpgp_signatures): ...here.  Change API to return sigs
after base 64 decoding.
(RCS_has_openpgp_signatures): New function.
* rcs.h (RCS_get_openpgp_signatures): Update proto.
(RCS_has_openpgp_signatures): New proto.
* server.c (server_send_signatures): Handle raw signatures and match
response documentation.
(server_base_signatures): Use RCS_has_openpgp_signatures.
* verify.c (verify_fileproc): Handle raw signatures.
* vers_ts.c (Version_TS): Save RCSNode in input finfo.