2.51.1.1:

General:
* Remove no_default_handler in some _WRAP_SIGNAL()s
  This allows application developers to simply override
  the default on_*() signal handlers for these signals too,
  as they can already with most other signals.
  If you are using, for instance, the -Wsuggest-override
  compiler option, watch out for new compiler warnings suggesting
  that your existing signal handler should now be marked with the
  override keyword - that means you should do so but you should
  also stop connecting the signal handler in your code.
  (Kjell Ahlstedt)
* Build: examples/Makefile.am: Re-insert the dispatcher examples
  (Kjell Ahlstedt)

Glib:
* Dispatcher: Don't cast a HANDLE to an int on Windows.
  (Kjell Ahlstedt) Bug #772074
* ObjectBase:
  - Remove connect_property_changed_with_return()
  and let connect_property_changed() return a sigc::connection.
  (Kjell Ahlstedt)
  - Use std::forward_list for interface class pointers.
  (Kjell Ahlstedt)
  - Replace extra_object_base_data map by instance data.
  (Kjell Ahlstedt)
* ObjectBase: overload get_property().
  (Marcin Kolny)
* Main, IOSource: autodeduce type of fd field.
  (Marcin Kolny) Bug #770274
* Settings: Add property_settings_schema(), and update
  signal_changed().
  (Kjell Ahlstedt)
* Settings: Make set_enum() + set_flags() usable
  (djb) Bug #774647
* SettingsSchemaKey: Add missing value/range methods
  (Daniel Boles) Bug #774903
* SignalProxyNormal: Remove connect_() and connect_notify_(),
  adding connect_impl().
  (Kjell Ahlstedt)
* Rename SignalProxyDetailed to SignalProxyDetailedBase, and
  SignalProxyDetailedAnyType to SignalProxyDetailed.
  Remove SignalProxyDetailed# aliases (# = 0..6).
  (Kjell Ahlstedt)
* Source: Replace extra_source_data by instance data.
  (Kjell Ahlstedt) Bug #561885

Gio:
* ActionMap::add_action_vfunc(): Const correction.
  (Murray Cumming)
* Application: Add dbus_register/unregister_vfunc.
  (Ritesh Khadgaray, Kjell Ahlstedt) Bug #762191
* Menu: insert/prepend/add_item(): Const correction.
  (Murray Cumming)
* MenuAttributeIter: get_value(): Const correction.
  (Murray Cumming)
* MenuModel: get_item_atribute(): const correction.
  (Murray Cumming)
* RemoteActionGroup: Derive from Gio::ActionGroup.
  (Murray Cumming)

Gio::Dbus:
* Proxy: Fix memory leak in get_cached_property_names().
  (Kjell Ahlstedt) Bug #775210
* Proxy: Derive from (and implement) Gio::DBus::Interface.
  (Murray Cumming)