Fix pause/resume:

* Pausing would resume at 0:00. Don't reset `audio.src` unless we're changing tracks
* Keep .now-playing progress and controls open when paused
* Don't flash '0:00' as much while track loads.
* Spacing for speaker name
analytics with segment.io

TODO:
* logstash?
* `window.analytics.page` works, `segmentio.page` doesn't…
   the `segmentio` library logs garbage.
   Why am I using it over window.analytics?