Optionally add a time limit to any AutoStep or AutoStepGroup

[Zaque2]

I'd like to add a time limit as needed to any AutoStep or AutoStepGroup so that the step's setFinished() function is automatically called after the time limit if one is provided. I think the best way to do this is to overload the addStep function, but am certainly open to other paradigms if someone has a better idea for implementing this.