gpg: Add debug helper to --edit-keys's check sub-command.
* g10/keyedit.c (print_and_check_one_sig): Add arg "extended" and print an asterisk for the chosen selfsig. (check_all_keysigs): Add arg "only_selfsig" (keyedit_menu) <cmdCHECK>: Add optional arg "selfsig".
Using "check selfsig" prints only the self-signatures and indicates
the chosen selfsig with an asterisk.
- Signed-off-by: Werner Koch <wk@gnupg.org>