[aprssig] IGATEing weather

[Chris Kantarjiev]

OK, I'm at this again. CWOP has ... issues, so I thought I'd just change
my IGATE's filter to pass local weather. I tried

# filter t/mwn/CDRVLY/25

but was overwhelmed by packets I didn't care about. It only took a few
seconds to realize that most of the packets were "positionless" weather
packets.

Now, most of the associated stations *have* positions, so it shouldn't
be that hard to figure out that their weather packets don't fall into
my range specifier.

Am I missing something? Or is this just a hole in the implementation?

73,
chris