container: Deprecate resize mode

Resize modes don't work anymore, both because nobody ever uses them and
because the frame clock changed the way things work quite a bit. So we
don't want to advertise them as a good idea.

https://bugzilla.gnome.org/show_bug.cgi?id=708787

gtk/gtkstylecontext.c

@@ -1069,10 +1069,12 @@ gtk_style_context_set_invalid (GtkStyleContext *context,
 
   if (invalid)
     {
+      G_GNUC_BEGIN_IGNORE_DEPRECATIONS;
       if (GTK_IS_RESIZE_CONTAINER (priv->widget))
         _gtk_container_queue_restyle (GTK_CONTAINER (priv->widget));
       else if (priv->parent)
         gtk_style_context_set_invalid (priv->parent, TRUE);
+      G_GNUC_END_IGNORE_DEPRECATIONS;
     }
 }