gboolean addritem_folder_add_person ( ItemFolder *folder, ItemPerson *item );
ItemPerson *addritem_folder_remove_person( ItemFolder *group, ItemPerson *person );
gboolean addritem_folder_add_folder ( ItemFolder *folder, ItemFolder *item );
gboolean addritem_folder_add_group ( ItemFolder *folder, ItemGroup *item );
gboolean addritem_folder_add_person ( ItemFolder *folder, ItemPerson *item );
ItemPerson *addritem_folder_remove_person( ItemFolder *group, ItemPerson *person );
gboolean addritem_folder_add_folder ( ItemFolder *folder, ItemFolder *item );
gboolean addritem_folder_add_group ( ItemFolder *folder, ItemGroup *item );