[gtkmm] Created tag 3.89.3

[Murray Cumming <murrayc src gnome org>]

The unsigned tag '3.89.3' was created.

Tagger: Murray Cumming <murrayc murrayc com>
Date: Thu Jan 19 13:57:10 2017 +0100

    3.89.3

Changes since the last tag '3.89.2':

Kjell Ahlstedt (4):
      Gtk::TextIter: Make a real const_iterator
      Demos: Remove obsolete text from the TextView demo
      Gtk::TextIter: Use sigc::slot in forward/backward_find_char()
      Gtk::Grid: Add default values in attach()

Murray Cumming (2):
      Build: Require the latest cairomm.
      3.89.3