Swing Playback implementation using staff texts

Swing playback using staff texts implemented, facilitating local control over swing parameters. Also added tests for the same.
there have been additions to this Dialog, so QtCreator increased it. Decreasing it manually will make them resurrect in next change (done via QtCreator), even it that is just correcting a typo in some lable, i.e. nothing to do with the size of the dialogs. So I don#t think there#s anything that could sensibly be done about this.
Same for the other places where you had the same comment