[Trlog] Alt-D window appending calls

[k4ro at k4ro.net (K4RO Kirk Pickering)]

I also had the behavior reported by K1KY and W9WI with Alt-D,
and wound up switching from 6.73 to 6.72 for the last half of
the contest.  I kept calling W9REK5RC or some such appended 
call accidentally over and over again.  If keeping the call
in the Alt-D "on deck" is a new feature, it would be good to 
be able to disable it.  6.72 worked very well, and I was again
able to make good use of the new EXCHANGERADIOS function.

-Kirk  K4RO