Merge branch 'mg/gpg-richer-status'

The GPG verification status shown in "%G?" pretty format specifier
was not rich enough to differentiate a signature made by an expired
key, a signature made by a revoked key, etc.  New output letters
have been assigned to express them.

* mg/gpg-richer-status:
  gpg-interface: use more status letters

pretty.c

@@ -1230,8 +1230,12 @@ static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
 			switch (c->signature_check.result) {
 			case 'G':
 			case 'B':
+			case 'E':
 			case 'U':
 			case 'N':
+			case 'X':
+			case 'Y':
+			case 'R':
 				strbuf_addch(sb, c->signature_check.result);
 			}
 			break;