[Xastir] wx data display as continuous shades?

[Jason KG4WSV]

I don't know the terminology, but I've wondered how / how difficult it would
be to display APRS weather data the way TV stations do - for example, temp
data would be some pseudo-continuous shading based on relative temperature
(or wind speed, wind direction, rainfall accumulation, or whatever).

I'm not necessarily suggesting this for an xastir feature, mostly just
throwing it out here where some developers and weather types hang out and
maybe will comment.

-Jason
kg4wsv