gpg: Prepare for a new export option export-realclean.

* g10/options.h (EXPORT_REALCLEAN): New.  Also re-assign other values
to keep them more in sync with the corresponding import values.
* g10/export.c (parse_export_options): Add "export-realclean".
(do_export_stream): Call clean_all_uids directly with the options
arg.
* g10/import.c (import_one_real): Change for direct use of options in
clean_all_uids.
* g10/key-clean.c (is_trusted_key_sig): New.  Stub for now.
(clean_sigs_from_uid): Re-purpose self_only to a general options arg.
Implement EXPORT_REALCLEAN code path.
(clean_one_uid): Re-purpose self_only to a general options arg.
(clean_all_uids): Ditto.
* g10/keyedit.c (keyedit_menu): Use EXPORT_MINIMAL instead of a simple
flag.
(menu_clean): Re-purpose self_only to a general options arg.

* g10/keyid.c (fpr20_from_pk): Factor code out to ....
(fpr20_from_fpr): new.  Remove useless case for ARRAY being NULL.
* g10/tdbio.c (tdbio_search_trust_byfpr): Add arg fprlen and use
fpr20_from_fpr if needed.
(tdbio_search_trust_bypk): Pass 20 for the fingerprint length.
--

Note that this code has no function yet.  Another patch will follow to
extract the trusted-keys flag from the trustdb.

g10/options.h

@@ -416,12 +416,13 @@ EXTERN_UNLESS_MAIN_MODULE int memory_stat_debug_mode;
 #define EXPORT_ATTRIBUTES                (1<<1)
 #define EXPORT_SENSITIVE_REVKEYS         (1<<2)
 #define EXPORT_RESET_SUBKEY_PASSWD       (1<<3)
-#define EXPORT_MINIMAL                   (1<<4)
-#define EXPORT_CLEAN                     (1<<5)
+#define EXPORT_MINIMAL                   (1<<5)
+#define EXPORT_CLEAN                     (1<<6)
 #define EXPORT_DANE_FORMAT               (1<<7)
 #define EXPORT_BACKUP                    (1<<10)
 #define EXPORT_REVOCS                    (1<<11)
 #define EXPORT_MODE1003                  (1<<12)
+#define EXPORT_REALCLEAN                 (1<<13)
 
 #define LIST_SHOW_PHOTOS                 (1<<0)
 #define LIST_SHOW_POLICY_URLS            (1<<1)