[ESS] toolbar code should now work on Emacs 23

[Stephen Eglen]

I found the bug with the toolbar code in Emacs 23, and the SVN version
of ESS should now have a working toolbar.  Either grab the entire SVN,
or just the toolbar code from 
https://svn.r-project.org/ESS/trunk/lisp/ess-toolbar.el

(Remember to delete the ess-toolbar.elc file if you download this file.)

Stephen