function TweenGroup(paused, timeScale) {
		this._tweens = [];
		this.paused = paused;
		this.timeScale = timeScale;
		this.__onComplete = this._onComplete.bind(this);
	}
TweenGroup allows you to pause and time scale a collection of tweens or timelines. For example, this could be
used to stop all tweens associated with a view when leaving that view.

	myView.tweens = new createjs.TweenGroup();
	myView.tweens.get(spinner, {loop: -1}).to({rotation:360}, 500);
	myView.tweens.get(image).to({alpha: 1}, 5000);
	// ... make all tweens in this view run in slow motion:
	myView.tweens.timeScale = 0.1;
	// ... pause all this view's active tweens:
	myView.tweens.paused = true; // stop all tweens.

You can add a group to another group to nest it.

	viewTweenGroup.add(buttonTweenGroup);

Tweens are automatically removed from the group when they complete (ie. when the `complete` event fires).

@class TweenGroup
@param {Boolean} [paused] The initial paused property value for this group.
@param {Number} [timeScale] The intiial timeScale property value for this group.
@constructor