[Trlog] A default prefix for the callsigns

[Jari Koski OH6QU]

Anyone knows if it is possible to configure TR in a way that it puts a
default (editable) prefix to the callsign field? That would be a handy
feature in the domestic contests where 99% of worked stations are having the
same prefix e.g. OH... It saves you typing that very same prefix couple of
hundreds times per each domestic contest.

73,
Jari OH6QU