renamed contest 'foc' to 'focmarathon', added keydefinitions

- Thanks OK1RR.
fix scoring for FOC marathon

1 point per QSO
2 points per country
5 points per continent
5b qso gets 10 points bonus
6b qso gets 15 points bonus
Gx4FOC joker counts double
initialize complete call statistics

- rescoring works by rereading the logfile and building the
  whole statistical data from there. Until now band and country data
  for worked calls got not reinitialized. Therefore we got wrong result
  when deleting the last call and rescoring.