Broccoli fun

@chadhietala i know you have been working on this aswell, but i haven't been happy with the available broccoli primitives. I have been noodling for some time, so finally took the time to experiment some. RSVP was just an obvious place for my to experiment. I hope i have not stepped on your progress.

I would love you thoughts on broccoli-stew

- [ ] prepend license file (we will add something like `map` to broccoli-stew shortly)
This is never going to get called. See https://github.com/stefanpenner/broccoli-stew/issues/6