Audio play line should match wave

From Eric Schwarzenbach on 2015/10/11 00:02:53 +0000

Right now the audio wave shown is the full width of the screen but the playback bar is not. They should match. There is no good reason we should not see the bar crossing spikes in the bar as we hear the sound spike. It is unintuitive and disconcerting that they don’t.

Copied from original feature request: