Feature request: add option to have "zoom" and "move" buttons

I think it'd be a nice feature to allow the timeline to have 4 zoom in/out + move left/right button. I know it's not extremely hard to add it ourselves, but it sounds like a feature that could benefit other users as well.

I was particularly interested in doing it since I don't have a way to zoom in using my laptop (there is no middle mouse button), and I suspect a lot of other people also don't have a way to zoom in using their laptop. Just a simple navigation system would be nice.

Another idea is to just have a scale for allowing to zoom between the minimum and maximum zoom, like the one Google Maps has.