* gtk/Gtk.metadata : hide TreeModel.RowsReordered signal so we can do
a correct implementation while maintaining compat with the existing
broken "NewOrder" parameter.
* gtk/ListStore.custom : manual RowsReordered signal implementation.
* gtk/RowsReorderedHandler.cs : manual implementation for preserve compat
in the Args class. Adds NewChildOrder to replace the broken ChildOrder.
* gtk/TreeModel.custom : manual RowsReordered signal declaration.
* gtk/TreeModelFilter.custom : manual RowsReordered signal implementation.
* gtk/TreeModelSort.custom : manual RowsReordered signal implementation.
* gtk/TreeStore.custom : manual RowsReordered signal implementation.
[Fixes#78512]
svn path=/trunk/gtk-sharp/; revision=75837