Tweaked protocol timers for one-wire serial.

- rx3s to wait up to 100ms (instead of 500ms) for program box to connect. after that, it waits up to 500ms to subsequent messages (eg. heartbeat).
- program to poll for connection with a period of (50ms interval + 20ms timeount) ~= 70ms.
- program box to busy wait up to 20ms for a rx3s response (instead of 200ms). the current cfg takes around 5ms to transmit, so there is roughly 4x headroom at this time.