Handle out-of-flow frame for interactive documents #362

As far as I can tell, when creating a new frame, it is automatically added to the "flow" of the presentation.

But this is not required for the target of a link : there are situations where the target frame of a link should only appear when manually activating the link. And not automatically as part of the presentation flow. This is especially true for interactive presentations.

(削除) Ideally (?) the transition after such "out-of-flow" frame should go back to the previous frame. (削除ここまで)

Maybe we could leverage the "Show in frame list" feature to consider a hidden frame as "out-of-flow" and not showing it at part of the linear flow of the presentation ?