Don't perform newly added actions if player is paused

[eoghanmurray]

I've a scenario where newly added events which are coming in after the current play position are affecting the player state even when the player is paused.
I believe the correct thing to do (as per this pull request) is not to execute them until the player is resumed.
I see that starting the timer.start(); line was added as part of #161 but I can't quiet understand what the idea was there?
I've changed it to instead only queue up the event if the timer is currently executing, which makes more sense to me, but I might be missing something?

[Yuyz0112]

@eoghanmurray Yes, I believe it's a bug in the original design.

[Yuyz0112]

Thanks!