Make GtkNotebook able to drop detached tabs anywhere. Bug #360225.

Make GtkNotebook able to drop detached tabs anywhere. Bug #360225.

2006-12-28  Carlos Garnacho  <carlosg@gnome.org>

        Make GtkNotebook able to drop detached tabs anywhere. Bug #360225.

        * gtk/gtkwidget.c (gtk_widget_class_init): add "drag-failed" signal.
        * gtk/gtkmarshalers.list: add new marshaler definition.
        * gtk/gtkenums.h: add GtkDragResult enum.

        * gtk/gtkdnd.c (gtk_drag_drop_finished): emit "drag-failed" if DND
        operation wasn't successful.
        (_gtk_drag_source_handle_event) (gtk_drag_drop)
        (gtk_drag_selection_get) (gtk_drag_cancel) (gtk_drag_key_cb)
        (gtk_drag_grab_broken_event_cb) (gtk_drag_grab_notify_cb)
        (gtk_drag_button_release_cb) (gtk_drag_abort_timeout): tell
        gtk_drag_drop_finished() the operation result.

        * gtk/gtknotebook.c (gtk_notebook_drag_failed): new function.
        (gtk_notebook_drag_data_get): do not call window creation hook here.
        (gtk_notebook_init): do not set "application/x-rootwindow-drop"
        target, instead connect to "drag-failed".
        (gtk_notebook_draw_focus): fix potential crasher if cur_page is NULL.