Comment 7 for bug 1223903

I force pushed a rebase onto the above branch that takes into account Dan Wells' concern in comment #5 and my reply in comment #6. We lose the clever Marque.pm and instead the changes go directly into marc_export. It is cleaner this way, and we don't need an install-exec-hook in Makefile.am.

As far as I am concerned, this one is ready for testing.