idea: Action structure includes step used to process it

[michaeljb]

after a step processes an action, that action could be updated so it knows which step processed it. Then when the game is re-loaded in the future, instead of iterating through steps to find one that can process it, it is just a fast lookup to grab the right step.

downside: if logic changes which step would process an action, an action would continue to be processed with the same step that processed it when it was created