***THE fail_safe.ino IS NOW WORKING CORRECTLY AND SHOULD BE FINALIZED*** (I hope!!!)

changes:
1. MOST IMPORTANT CHANGE: the pro-mini will ONLY set the state once the TX signal is stable (i.e. 5 consecutive signals).
2. initial state will always be MANUAL until the TX is switched on.
3. added info on how to RX works and reacts to the TX being switched on and off
4. changed the pulseIn timeout length to capture more pulses. it now gets ~90% of the pulses. i am fine with that. the system works good and in this case, perfect is the enemy of good.

Signed-off-by: rkburnside <richard@burnsides.org>