Tweens - Example showing how to use the tween events, onStart, onLoop and onComplete.
Lots of documentation fixes in the Tween class.
Tweens fire an onLoop event if they are set to repeat. onComplete is now only fired for the final repeat (or never if the repeat is infinite)
Tween.onStart is now called when the tween starts AFTER the delay value, if given (thanks stevenbouma)
