xim: Compose results of any length, StatusNone styles; ibus: no cursor size check

A Compose sequence whose result is more than one character has no
keysym, so xkb_compose_state_get_one_sym gave nothing and the result was
lost; the UTF-8 the compose state holds is committed instead.  Clients
that ask for a StatusNone style — fcitx5 offers them — failed to create
an input context; the three preedit styles come in both status flavours
now.  IBus SetCursorLocation returned an error for a negative width or
height that nothing reads and no client ever waits for.

ibus.c

@@ -786,9 +786,6 @@ handlecursor(DBusConnection *c, DBusMessage *m, Ictx *ctx)
 		DBUS_TYPE_INVALID))
 		return handleerror(c, m, DBUS_ERROR_INVALID_ARGS,
 			"SetCursorLocation expects four integers");
-	if(w < 0 || h < 0)
-		return handleerror(c, m, DBUS_ERROR_INVALID_ARGS,
-			"cursor dimensions must not be negative");
 	setcursor(ctx, x, y, h);
 	return reply(c, m, DBUS_TYPE_INVALID, nil);
 }