[gtkmm] Created tag 3.21.4

[Murray Cumming <murrayc src gnome org>]

The unsigned tag '3.21.4' was created.

Tagger: Murray Cumming <murrayc murrayc com>
Date: Thu Jul 21 12:39:44 2016 +0200

    3.21.4

Changes since the last tag '3.21.3':

Kjell Ahlstedt (7):
      class_gtkobject.m4: Add _CUSTOM_WRAP_FUNCTION and _NO_WRAP_FUNCTION
      ApplicationWindow: Define it as a _CLASS_GTKOBJECT
      Gtk::FlowBox, ListBox: Add bind_model() and bind_list_store()
      Gtk::FlowBox, ListBox: Include glibmm/exceptionhandler.h
      Deprecate Gtk::UIManager, Gtk::Action etc.
      Improve the documentation of deprecation
      Build: Fix silent builds

Murray Cumming (1):
      3.21.4