gtkmm 2.11/12 API freeze

Today is Gnome 2.19/2.20 API freeze day, as per the schedule, and I’ve just released the API-frozen glibmm 2.13.x and gtkmm 2.11.x tarballs. This is always stressful, but Jonathan Jongsma and Marko Anastasov reviewed the new glibmm 2.14 API and new gtkmm 2.12 API, finding some of my inevitable errors in the API and the documentation.

Minor changes can still be made, with permission from the Gnome release-team, but only if you tell us about problems before the final stable releases in September.