Update all the SDR implementation to use it.
This was getting pretty ugly with code getting copy&pasted in all the SDR
implementations. Unify it all and give it a simpler API. Linked list works out
much simpler than the circular buffer. Also, simplify copying the overlap region
around by just using a separate buffer (it's only a few hundred bytes long, so
the double copy is not a big deal).
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.
Oliver Jowett
Oliver Jowett