Reduce use of Glib types in marpa.w
Reduce use of Glib types in marpa.w

jeffreykegler/kollos,pczarn/kollos,jeffreykegler/kollos,jeffreykegler/kollos,jeffreykegler/kollos,pczarn/kollos,jeffreykegler/libmarpa,jeffreykegler/kollos,jeffreykegler/libmarpa,jeffreykegler/libmarpa,jeffreykegler/libmarpa,jeffreykegler/libmarpa,pczarn/kollos,pczarn/kollos,pczarn/kollos