Moving QMidi transport bar with arrow keys

Hi Bruno!

Using QMidi to transcribe songs I've noticed that you can't move the transport bar with arrow keys (only with the mouse).

I think you could implement it - this would be very cool to have the option of using the keyboard to forward or backward the time of the song (and with the option of how much, for example, 1s, 5s, 10 seconds in both directions).

Hope you can do it.

Best regards,

João Luiz