Why doesn't MeteorSubs work inside autorun?

[timadye]

MeteorSubs doesn't seem to work when called from inside a Tracker.autorun (trackGameState): instead, it calls the server's publish in an infinite loop.
Fortunately Meteor's native subscribe should do what we went - at least inside the Tracker: it doesn't republish the same subscription, and unsubscribes when the state changes again (ie. we leave the endGame view).

We work round this in history.js#L68, but it would be good to understand what's wrong or else report as a MeteorSubs bug.