[no subject]

We need to either make GnomeCanvas depend on libbonoboui and implement
BonoboCanvasItems in libgnomecanvas, or we need to make some canvas item
behavior more overridable.

The "dirtying" mechanism is problematic currently for bonobo.  An
overridable set_dirty() class method would be nice.  The default
implementation would be the existing gnome_canvas_item_request_update.
BonoboCanvasComponent needs something like this so it can step in and
proxy intelligently without having to kluge up a server side canvas like
it currently does.  

Also, if we can't nuke gnome_canvas_request_redraw outright, (perhaps by
having ::update() return a UTA?) then we need a mechanism for out of
process CanvasComponents to proxy redraw requests as well.
  
Mike