Attempts at plumbing

Pull request-ing just to let you know of status: while I have the Atlas class generating semi-reasonable state / input / output frames, I'm stuck on figuring out what plumbing is required to keep various controllers happy (e.g. in the runAtlasBalancing demo). I feel like there should be a way to maintain a significant divide between the IO and state of Atlas itself, and the state/IO of the attached systems, but my efforts to make each of the controllers comply with this have been unsuccessful -- I'll take a fresh look tomorrow if I survive my other midterm.