SoftRF version MB166

[Moshe Braner]

Now on github.  The main change is the addition of the ADS-L protocol.  This is not important for most of us at this time, but that may change in the future.  (See the thread in this Group about ADS-B.)

For now ADS-L is only used in Europe (AFAIK), but this version of SoftRF uses the same frequencies and time slots as OGNTP, as is the case in Europe.

If ADS-L is set as the main protocol, SoftRF both transmits and receives it.  If set as the alt-protocol, it is transmit-only, once every 16 seconds.  Only the following protocols can be mixed as main and alt:  Latest, Legacy, OGNTP, and ADS-L.

Version MB166 includes a few other small changes, including:

* no collision alarms for TIS-B, and fallback to the vector algo for ADS-R

* added an option (hidden setting) to convert $GNxxx to $GPxxx for output of GNSS NMEA sentences

* more checks to ensure no transmission before GNSS fix