vdom.Helper: update() => performance

I think we can further increase the performance, in case we add a map for the new & old vnode trees.

object keys with the structure:

ìd: {vnode, parentId, parentIndex, parentVnode}

(parentId is a bit redundant (same as parentVnode.id)).

This way we would ensure, that vnode trees only get recursively parsed 3 times

1. creating the map: new tree
2. creating the map: old tree
3. dynamically parsing the new tree

right now, there are additional sub tree parsings in place (to find moved nodes).