API Access to GdkPixbuf in GnomeCanvasPixbuf

[Marc Mulcahy <marc mulcahy sun com>]

In preparation for platform alpha, I have reviewed libgnomecanvas for any 
possible API changes necessary to implement accessibility on its 
widgets.  the only issue I discovered is that there is currently no API to 
access the GdkPixbuf contained in a GnomeCanvasPixbuf widget.  This would 
be required for screen readers or other assistive technology which needs to 
uniquely identify an image, or which in some other way needs access to 
it.  Could this be added?

Marc