[gtkmm] Broken links

[Lance Arsenault <lanceman bev net>]

FYI:

 http://www.gtkmm.org/docs/gtkmm-2.4/docs/

      links to:  http://cvs.gnome.org/lxr/source/gtkmm/CHANGES
                      
http://cvs.gnome.org/lxr/source/gtkmm-root/base/PORTING
                      http://cvs.gnome.org/lxr/source/gtkmm/ChangeLog
      which are not found.