Simplifying FlxDelay

[IQAndreas]

I find it unnecessary that FlxDelay extends Sprite, when it can be made much more simple and efficient by adding a single static dispatcher that provides the event for all FlxDelay instances: https://gist.github.com/1525275

Or another solution, why does it extend Sprite and listen to ENTER_FRAME instead of extending FlxPlugin and using it's "update" method?

An an additional idea for FlxDelay, the "newDuration" parameter of "reset" should be optional, so by default, if no parameter is passed, the timer will be reset to the same amount of time it was when first initialized.