* kbx/keybox-defs.h (_keybox_openpgp_key_info): Add field ALGO.
* kbx/keybox-openpgp.c (parse_key): Store algo.
* kbx/kbxutil.c (dump_openpgp_key): Print algo number.
* kbx/keybox-dump.c (_keybox_dump_blob): Print identical Sig-Expire
value lines with a range of indices.