* packet.h, trustdb.h, trustdb.c (trust_string): New. Return a string

like "fully trusted", "marginally trusted", etc. (get_min_ownertrust):
New.  Return minimum ownertrust. (update_min_ownertrust): New.  Set
minimum ownertrust. (check_regexp): New.  Check a regular epression
against a user ID. (ask_ownertrust): Allow specifying a minimum value.
(get_ownertrust_info): Follow the minimum ownertrust when returning a
letter. (clear_validity): Remove minimum ownertrust when a key becomes
invalid. (release_key_items): Release regexp along with the rest of the
info. (validate_one_keyblock, validate_keys): Build a trust sig chain
while validating.  Call check_regexp for regexps.  Use the minimum
ownertrust if the user does not specify a genuine ownertrust.

* pkclist.c (do_edit_ownertrust): Only allow user to select a trust level
greater than the minimum value.

* parse-packet.c (can_handle_critical): Can handle critical trust and
regexp subpackets.

* trustdb.h, trustdb.c (clear_ownertrusts), delkey.c (do_delete_key),
import.c (import_one): Rename clear_ownertrust to clear_ownertrusts and
have it clear the min_ownertrust value as well.

* keylist.c (list_keyblock_print): Indent uid to match pub and sig.

g10/import.c

@@ -671,7 +671,7 @@ import_one( const char *fname, KBNODE keyblock,
 	       the keyring and trustdb are out of sync.  It can also
 	       be made to happen with the trusted-key command. */
 
-	    clear_ownertrust (pk);
+	    clear_ownertrusts (pk);
 	    revalidation_mark ();
 	  }
         keydb_release (hd);