* g10/parse-packet.c (parse_signature): Allow for v5 signatures.
* g10/sig-check.c (check_signature_end_simple): Support the 64bit v5
byte count.
* g10/sign.c (hash_sigversion_to_magic): Ditto.
(write_signature_packets): Request v5 sig for v5 keys.  Remove useless
condition.
(make_keysig_packet): Request v5 sig for v5 keys.