[gtkmm] NEWS: Mention API additions in 3.12

[Murray Cumming <murrayc src gnome org>]

commit c532b3b89b3df2d999ec8432d13e7124da8c12be
Author: Murray Cumming <murrayc murrayc com>
Date:   Mon Apr 14 09:28:27 2014 +0200

    NEWS: Mention API additions in 3.12

 NEWS |   74 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 74 insertions(+), 0 deletions(-)
---
diff --git a/NEWS b/NEWS
index 409fbcd..eda33e5 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,77 @@
+3.12:
+
+API additions since 3.10:
+
+Gtk:
+* Add ActionBar.
+  (Juan R. García Blanco) Bug #723124
+* Application:
+  - Added set_accel_for_action(), get/set_accels_for_action() and
+  list_action_descriptions().
+  (Murray Cumming)
+  - Add set_accels_for_action(), deprecating add_accelerator().
+  (Murray Cumming)
+* Assistant: Add use-header-bar property.
+  (Juan R. García Blanco)
+* Box: Add get/set_center_widget() and unset_center_widget().
+  (Juan R. García Blanco)
+* Builder: Add expose_[object|widget](), [set|get]_application().
+  (Kjell Ahlstedt)
+* Button: Add set_image_from_icon_name() with a use_fallback argument.
+  (Kjell Ahlstedt)
+* CellArea: Add signal_apply_attributes().
+  (Kjell Ahlstedt)
+* Dialog: Add get/set_header_bar() and the
+  use_header_bar property.
+  (Juan R. García Blanco)
+* Entry:
+  - Add the max-width-chars property.
+  - Add get/set_max_width_chars() and the property.
+  (Juan R. García Blanco)
+  - Add set/get_attributes() and the property.
+  (Kjell Ahlstedt)
+* Add FlowBox and FlowBoxChild.
+  (Juan R. García Blanco) Bug #723801
+* HeaderBar: Addd get_decoration_layout(), get_has_subtitle(),
+  set_decoration_layout() and set_has_subtitle() and properties.
+  (Juan R. García Blanco) Bug #723199
+* IconInfo: Add is_symbolic().
+  (Juan R. García Blanco)
+* MenuButton:
+  - Add get/set_popover() and unset_popover() and the property.
+  - Add get/set_use_popover() and the property.
+  (Juan R. García Blanco)
+* PlacesSidebar: Add local-only object property and get/set methods.
+  (Juan R. García Blanco) Bug #723893
+* Add Popover.
+  (Juan R. García Blanco) Bug #723058
+* SelectionData: Add get_data(int& length).
+  (Kjell Ahlstedt)
+* Settings: Add gtk-decoration-layout, gtk-shell-shows-desktop
+  and gtk-dialogs-use-header properties.
+  (Juan R. García Blanco) Bug #723397
+* Stack: Add get_transition_running(), get_child_by_name() and
+  the transition-runnning property.
+  (Juan R. García Blanco) Bug #723397
+* ToolItem: Add unset_proxy_menu_item().
+  (Kjell Ahlstedt)
+* Widget:
+  - Added get/set_margin_start/end() and properties.
+  (Murray Cumming)
+  - Added scale-factor property.
+  (Murray Cumming)
+* Window: Add is_maximized() and the is-maximized property.
+  (Juan R. García Blanco)
+
+
+Gdk:
+* Device: Add get_last_event_window().
+  (Murray Cumming)
+* Pixbuf:
+  - Add get_byte_length() and create_from_resource().
+  (Murray Cumming)
+
+
 3.12.0 (stable):
 
 * Application: Add set_accels_for_action(), deprecating add_accelerator().