* plug-ins/gfig/gfig-dialog.c
* plug-ins/gfig/gfig-dialog.h
* plug-ins/gfig/gfig-dobject.c
* plug-ins/gfig/gfig-dobject.h
* plug-ins/gfig/gfig-types.h
* plug-ins/gfig/gfig.c
* plug-ins/gfig/gfig.h: replace the crappy DAllObjs struct by a GList.
  Makes the code cleaner and less error prone.