* libnautilus-private/nautilus-authn-manager.c:
	(construct_password_dialog,
	present_authentication_dialog_blocking, mark_callback_completed,
	authentication_dialog_button_clicked,
	present_authentication_dialog_nonblocking,
	vfs_async_authentication_callback, vfs_authentication_callback,
	nautilus_authentication_manager_initialize): Converted to use the
	new module callback API. Use async callbacks instead of our own
	mechanism to achieve the same effect.