Magnitude conversion now happens immediately when sample data is
received, so there is no risk of newly received data clobbering old
data under CPU overload.
This is possible now that the SBS output doesn't rely on the global block timestamp;
the output will look like this:
MSG,8,111,11111,4AC954,111111,2015/02/08,17:57:53.917,2015/02/08,17:57:53.936,,,,,,,,,,,,0
MSG,7,111,11111,392AEB,111111,2015/02/08,17:57:53.744,2015/02/08,17:57:53.936,,15375,,,,,,,,,,0
MSG,8,111,11111,392AEB,111111,2015/02/08,17:57:53.917,2015/02/08,17:57:53.936,,,,,,,,,,,,0
MSG,6,111,11111,800387,111111,2015/02/08,17:57:53.919,2015/02/08,17:57:53.936,,,,,,,,4745,0,0,0,0
where the "receive timestamp" (first time column) goes backwards to reflect the original reception
time of the delayed message, but the "forwarded timestamp" (second time column) reflects the actual
forwarding time.
the message being emitted immediately.
Fix computation of reception time so it's more sensible (the block timestamp
is some time after reception of the _end_ of the block, not the start) - this
means that message-emission times are always later than message-reception
times in SBS output, which is a bit more sensible.
Use clock_gettime in preference to ftime.
(except in --net-verbatim mode, where we emit them all)
Move aircraft tracking into track.[ch].
Clean up references to "interactive mode" when tracking
aircraft - we always track aircraft, even in non-interactive
mode.
since we have 8 bits spare, so there's no chance of confusing it
with an ICAO address, and we can safely use the filter table to match
future messages without also matching equivalent ICAO addresses.
Switch signalLevel back to a power measurement, don't put SNR in there.
But make it a 0.0 - 1.0 double so we're not scaling everywhere.
Adjust for the amplitude offset when calculating power.
Adapt everything else to the new scheme.
This is adapted from the FlightAware fork, with some cleanup and
modifications needed to work with the net-cleanup changes.
Inclusion of "verbatim" TSV data read from an AVR-format input
connection is not supported.