char * vs. unsigned char * warnings. The GNU coding standards used to
say that these mismatches are okay and better than a bunch of casts.
Obviously this has changed now.
sm/
* call-dirmngr.c (inq_certificate): Add new inquire SENDCERT_SKI.
* certlist.c (gpgsm_find_cert): Add new arg KEYID and implement
this filter. Changed all callers.
* certchain.c (find_up_search_by_keyid): New helper.
(find_up): Also try using the AKI.keyIdentifier.
(find_up_external): Ditto.