Timeline view is difficult to scroll around on #347
Description
I like the new timeline view, but the scrolling behavior is a little wonky. I think it needs to be much harder to zoom in and out. Ideally it would lock either horizontal scrolling or zooming, so that you can scroll the timeline without zooming at the same time. Maybe it should also require more of a vertical scroll to actually activate zooming.
Another idea would be to make scrolling on the timeline itself only do panning (this would also fix #346), and make it so that to zoom you have to scroll or drag on the top bar. This is a common UI for zooming a chart.