[aprssig] APRS Priority bit

[Robert Bruninga]

> If you wanted to limit digipeating other 
> traffic than positions, you'd need to 
> memorize the priority bit per station 
> sent in the position packets to allow 
> messages of those stations to be digipeated. 
> 
> Do you have much RAM to spare?

My thinking is that messages are always priority traffic.
Positions and objects are less so and can be separated into
High and low priority..

bob