Debug.ShowHint support non-string (#747)

* update Debug.ShowHint

support all things which can `tostring`

* fix Debug.Message crash on no param

libdebug.cpp

@@ -176,10 +176,12 @@ int32_t scriptlib::debug_set_ai_name(lua_State *L) {
 }
 int32_t scriptlib::debug_show_hint(lua_State *L) {
 	check_param_count(L, 1);
-	check_param(L, PARAM_TYPE_STRING, 1);
 	duel* pduel = interpreter::get_duel_info(L);
+	lua_getglobal(L, "tostring");
+	lua_pushvalue(L, -2);
+	lua_pcall(L, 1, 1, 0);
 	pduel->write_buffer8(MSG_SHOW_HINT);
-	const char* pstr = lua_tostring(L, 1);
+	const char* pstr = lua_tostring(L, -1);
 	int len = (int)std::strlen(pstr);
 	if (len > SIZE_HINT_MSG - 1)
 		len = SIZE_HINT_MSG - 1;