Possible addition to drag and drop

[Brett Hall <swizin rain org>]

Hi-
I'm working on a user-customizable toolbar widget for gtk+ and need to
add a few things to drag and drop in order to make it work the way I
want.  The additions would be functions to get the drag dest and drag
source info (ie the arguments used in gtk_drag_dest_set() and
gtk_drag_source_set()) for a widget.  I need this because I need to be
able to assign new source and destination targets for the widgets on the
toolbar while the toolbar is in customization mode and then return the
widgets to the original targets when the toolbar leaves customization
mode.  I also noticed in gtk_dnd.h that there is a comment about adding
functions to allow the registering of targets using target lists instead
of arrays, I figured I would go ahead and implement these too while I
was at it (they'll come in handy when changing the toolbar child widget
targets).  I just wanted to make sure that there wasn't some reason why
this functionality doesn't already exist in drag and drop.
-brett