gpg: Prepare to pass additional context to the list functions.
* g10/keylist.c (struct sig_stats): Rename to keylist_context and add field check_sigs. (keylist_context_release): New. (list_all): Set listctx.check_sigs and call release func. (list_one): Ditto. (locate_one): Ditto. (list_keyblock_print): Use .check_sigs field. Repalce arg opaque by listctx. (list_keyblock): Ditto. Make static. (list_keyblock_direct): New. * g10/keygen.c (do_generate_keypair): Replace list_keyblock by list_keyblock_direct.
This is in preparation for the server mode and for a patch to speed up
--list-sigs.
- Signed-off-by: Werner Koch <wk@gnupg.org>