Minor commit: Added class to play/pause button to enable toggling
Bug fix: Timeline clicking issue resolved

* Fixed an issue where depending on where you clicked on the timeline it
occassionally wouldn't start playback. This was due to bad source
detection handling. I've now switched to explicitly checking whether the
timeline was clicked on or whether an event box was clicked on to ensure
that 2 requests for event playback don't fire.
* Removed some old commented out code which is no longer needed