* certchain.c (gpgsm_validate_chain) <gpgsm_cert_use_cer_p>: Do
not just warn if a cert is not suitable; bail out immediately.
* call-dirmngr.c (isvalid_status_cb): New.
(unhexify_fpr): New. Taken from ../g10/call-agent.c
(gpgsm_dirmngr_isvalid): Add new arg CTRL, changed caller to pass
it thru. Detect need to check the respondert cert and do that.
* certchain.c (gpgsm_validate_chain): Add new arg FLAGS. Changed
all callers.