[aprssig] UIDIGI flood and trace options

[Cap Pennell]

> UIFLOOD OPTIONS = 4?  We want to have ID enabled on UIFLOOD so
> that SSn-N packets are partially traced as noted above...  It
> appears to me that this means set bits 1 and 2?  Yes, this makes
> the packet grow, but over the years, I have learned that it is
> more important to be able to trace the network than be overly
> brief with packets.

We like the results we see with UIDIGI settings of 
UIFLDFL 2
UITRFL 2

73, Cap KE6AFE