Now it's *actually* possible to see what's happening.

For the buggery that was induced by console.log() applied to deep arrays, see http://feonixrift.wordpress.com/2013/08/19/console-log-is-not-the-time-machine-i-was-looking-for/
Much better with JSON.stringify
I'm afraid it works again. Deep copy when using memoization, natch?
Tossed off the debugging.
DOM flattener and tweak to deep copy. (byebye JSON)
Out of memory and Maximum call stack size exceeded. Need to cut recursion.