[Xastir] More wx decoding problems

[Matt Werner]

I had commented a couple of weeks ago on the fact that xastir doesn't appear
to show the 3-hr baro change as my Ultimeter 2100 displays it.

I noticed yesterday that it has similar problems with rainfall.  xastir is
reporting 0.20 inch/mid, 0.20 inch/hr, and 0.20 inch/day, even though those
values are many days old now.  I know from experience if I exit xastir and
restart it that the values will reset to 0, so for some reason it is holding
on to old values.

I will add this as a bug @ Sourceforge when I have a chance, but wanted to
make the comments on it here now.

I would be more than happy to provide some testing data from my Ultimeter
2100.  Right now it is running in complete mode, but I can switch it for
other data if needed.

73 - Matt