* gladeui/glade-placeholder.[ch]: added packing action list to GladePlaceholder

* gladeui/glade-popup.c: added packing actions to placeholder popup

* gladeui/glade-widget-adaptor.[ch]: added glade_widget_adaptor_pack_actions_new ()

* gladeui/glade-widget.c: use new function glade_widget_adaptor_pack_actions_new () in
  glade_widget_set_packing_actions()

* plugins/gtk+/glade-gtk.c: take into acount placeholders get paking actions
  glade_gtk_box_notebook_child_insert_action() and glade_gtk_table_child_insert_action() fixed.

svn path=/trunk/; revision=1339