gpg: Support key flags for RENC, TIME, and GROUP.
* g10/packet.h (PUBKEY_USAGE_RENC): New. (PUBKEY_USAGE_TIME): New. (PUBKEY_USAGE_GROUP): New. * g10/getkey.c (parse_key_usage): Set the new key flags. * g10/keyedit.c (show_key_with_all_names_colon): Show the new key flags. * g10/keyid.c (usagestr_from_pk): Ditto * g10/keylist.c (print_capabilities): Ditto. * g10/keygen.c (parse_usagestr): Parse line and set new flags. (quickgen_set_para): Show flags.
See draft-koch-openpgp-2015-rfc4880bis-00 for the current version.
Actually these flags have been in the draft for years now. This patch
is a first step to make use of them.