Bug-fix request - Reset sequencer scrollbar at song load

[BigDplayboy]

There is this bug which is annoying since the first use of Buzz and the worst is, it's very easy to fix.

How to reproduce:
1. Load a track with many tracks in the sequencer-view, more than fit on your screen.
2. Scroll some tracks to the right
3. Load a song with very few tracks or make a new song.
4. In the sequencer view you can't see the first tracks and you are unable to scroll to them, because there is no scrollbar. But internally the scrollbar offset is still set to the value that corresponds with the many-tracks song.

To fix:
Reset the scrollbar value when loading a song.

[Evelon]

Yeah, that is a pretty annoying bug if you use many tracks.

[mridlen]

I've been in the habit of closing down Buzz completely between tracks, since way back in the day when it used to crash and hang the audio driver when I did that.