move treeversal bits to render-graphs.js
move treeversal bits to render-graphs.js

1mentat/descartes,1mentat/descartes,gcnonato/descartes,gcnonato/descartes,brad811/descartes,gcnonato/descartes,brad811/descartes,brad811/descartes,obfuscurity/descartes,obfuscurity/descartes