gobject: add support for g_auto() and g_autoptr()

Add support to libgobject types for the new cleanup macros.

https://bugzilla.gnome.org/show_bug.cgi?id=743640

glib/glib-object.h

@@ -35,6 +35,8 @@
 #include <gobject/gvaluearray.h>
 #include <gobject/gvaluetypes.h>
 
+#include <gobject/gobject-autocleanups.h>
+
 #undef __GLIB_GOBJECT_H_INSIDE__
 
 #endif /* __GLIB_GOBJECT_H__ */

gobject/Makefile.am

@@ -61,6 +61,7 @@ libgobject_2_0_la_DEPENDENCIES = $(gobject_win32_res)
 #
 # GObject library header files for public installation
 gobject_public_h_sources = \
+	gobject-autocleanups.h	\
 	glib-types.h		\
 	gbinding.h		\
 	gboxed.h		\

gobject/gobject-autocleanups.h

@@ -0,0 +1,26 @@
+/*
+ * Copyright © 2015 Canonical Limited
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the licence, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Ryan Lortie <desrt@desrt.ca>
+ */
+
+#if !defined (__GLIB_GOBJECT_H_INSIDE__) && !defined (GOBJECT_COMPILATION)
+#error "Only <glib-object.h> can be included directly."
+#endif
+
+G_DEFINE_AUTO_CLEANUP_FREE_FUNC(GStrv, g_strfreev, NULL)
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(GObject, g_object_unref)
+G_DEFINE_AUTO_CLEANUP_CLEAR_FUNC(GValue, g_value_unset)