[gtkmm] Created tag 3.15.3

[Murray Cumming <murrayc src gnome org>]

The unsigned tag '3.15.3' was created.

Tagger: Murray Cumming <murrayc murrayc com>
Date: Tue Dec 16 12:59:41 2014 +0100

    3.15.3

Changes since the last tag '3.15.2':

Juan R. García Blanco (4):
      Stack: Wrap hhomogeneous and vhomogeneous properties
      TextView: Wrap monospace property
      TextTag: Wrap missing properties
      ScrolledWindow: Wrap missing symbols

Kjell Ahlstedt (6):
      Add class Gtk::CssSection and enum Gtk::CssSectionType
      Gtk::CssProvider: Add CssProviderError and signal_parsing_error()
      Add GtkSelectionData to gtk_extra_objects.defs
      Fix some Doxygen warnings
      Add an empty line after @newin where it's missing
      Gtk::Dialog: Fix the constructors with DialogFlags

Murray Cumming (7):
      ScaleButton: Correct the constructor.
      ScaleButton: Add a constructor without the icons.
      ScaleButton: Document the constructors.
      Regenerate .defs.
      Regenerate .docs.xml.
      Widget: Added get_action_group() and list_action_prefixes().
      3.15.3