- merged the _MWERKS_ and the generic branch, only the loop head needs
different treatment
- created a constructor; the operator>> wouldn't have initialized all
variables in case of a broken default.fix.gz entry, so we would have
got a mixture of the broken one and the previous one; (valgrind
complained ...)
- move the automatic FGFix variable into the loop, so that the gets
cleanly constructed for every database entry.
- don't access fix.type before it is initialized
- updated the commented out debug output statements (they were copied
over from navlist.cxx but never adapted)
