Add support for the strikethrough attribute (SGR 9), using the new smxx

terminfo capability. This means there are now nine attribute bits, so
anything above 0xff uses an extended cell.

style.c

@@ -31,10 +31,8 @@ style_parse(const struct grid_cell *defgc, struct grid_cell *gc,
 	struct grid_cell	savedgc;
 	const char		delimiters[] = " ,";
 	char			tmp[32];
-	int			val;
+	int			val, fg, bg, attr, flags;
 	size_t			end;
-	int			fg, bg;
-	u_char			attr, flags;
 
 	if (*in == '\0')
 		return (0);