* plug-ins/gfig/gfig-style.c
* plug-ins/gfig/gfig-style.h: create a new function to get the current
  style instead of using a global pointer for this
  (gfig_context_get_current_style ())

* plug-ins/gfig/gfig-circle.c
* plug-ins/gfig/gfig-dialog.c
* plug-ins/gfig/gfig-dobject.c
* plug-ins/gfig/gfig.h: use this function everywhere it is needed. And
  remove the current_style field from GfigContext.

  (unrelated):
* plug-ins/FractalExplorer/Dialogs.h
* plug-ins/FractalExplorer/FractalExplorer.c: small cleanups