Aquastar/Dlux to send message with size based on the request type.
request:
> OW_NULL 1
> OW_GET_CFG 1
> OW_GET_STATS 1
> OW_SET_CFG sizeof(ow_msg.u.eeprom_cfg)
> OW_SET_STATS sizeof(ow_msg.u.eeprom_stats)

side effect is that autorepeat is now very fast since the heartbeats (OW_NULL) is now very short (and fast). will retune in the future CL.