2.8.9:

* FontButton: Fix the constructor that takes a font_name.
(Armin Burgmeier)
* AboutDialog: Fix a crash in set_url_hook().
  (Murray Cumming)
* Added --enable-atk=no option, to disable the build and use 
  of the atkmm API, for use in embedded environments.
  (Johannes Schimd, Murray Cuming, Openismus)
* Fix build when using --enable-api-default-signal-handlers with 
  glibmm. (Murray Cuming)