* gtk/gtkmenuitem.c: Made buildable and added support for adding children
of type "submenu"
* gtk/gtkwindow.c: Added support for custom tag "accel-groups" to add GtkAccelGroups
to the window.
* gtk/gtkcontainer.c: Added builder contextual warnings in buildable_add_child()
* gtk/tests/builder.c: Added tests for buildable menus (test that accelerators are
properly connected on stock items, test the menu hierarchy, test permission to
add alien/custom menuitem children).
* docs/reference/gtk/tmpl/gtkbuilder.sgml, docs/reference/gtk/tmpl/gtkwindow.sgml,
docs/reference/gtk/tmpl/gtkmenuitem.sgml: Updated docs for buildable submenus
and accel groups.
svn path=/trunk/; revision=21767
4858ae47e2