2646 - back to simpler eval

But we'll keep 'unqm' as a sense of the intended
state space we currently support.
2647 - new tack: incompletely-eval'd results

Retrying the idea of 2371 but in a different way.
2648 - eval retries incompletely-eval'd exprs
2649 - start partially eval'ing calls
2650 - incomplete args for destructured params
2651 - incomplete spliced args
2652 - use alreadyEvald to guard eval'd args