Rethink usage of Player's 'playOnActivate'

[MeoMix]

The usage of playOnActivate has become really muddled over time. Sometimes the player is just told to play. Other times it's told it should play in the near future and then is given a song to load. Other times, I fire an event through a channel which tells it to do the same thing. The event channel is necessary to prevent circular-references. That's a pretty big sign of bad stuff happening.

It would be good to sit down and think about how songs should be fed to the player and how it should consume them.