Parole should be Equipped with buttons ++15 seconds and --15 seconds

Especially on very long recordings, rewinding by only a few seconds is not easy.

Therefore Parole should be equipped with additional buttons to step forward/backward by a few seconds, say by 15 seconds.

I guess this is easily implemented (special cases only at the very beginning: limit to second 0) or at the very end (limit to end time of recording). The user's benefit would be great.