IGenericActuator: added goto() method that can manually change the current position

[joshtynjala]

Sometimes, I want to pause a tween and control it manually instead of letting it update automatically every frame. For instance, I might want to change the current position based on a Slider or another type of UI, like you would with video or audio.

Example usage

var actuator = Actuate.tween(target, duration, props);
Actuate.pause(actuator);
actuator.goto(0.5);

[jgranick]

How do you feel about using seek and time rather than using a ratio?

Also, I wonder if seeking should permanently affect the tween, like:

Actuate.tween(target, 2, props);
Actuate.seek(target, 1, props);
// 1 second remaining on the tween before complete

...I suppose this method might not work properly for rewinding or would trigger completion events when someone might want to be able to update to the end of the tween and back

This does raise an interesting question though of using Actuate with local instances rather than the global approach. I almost wish we could have local and global methods with the same name (like in AS3) so new Actuate().tween or Actuate.tween would both work.

[joshtynjala]

Yeah, seek/time would be fine by me. It's not a big deal if I need to manually convert between ratio/time.