Bug: as per React it should be possible to change roots

[Havunen]

NervJS:
https://codesandbox.io/s/m31owy1wvj (link fixed)

React: ( See console logs )
https://jsfiddle.net/a2ay2fh6/

expected result: Nerv should be able to change root nodes.
For more tests on similar manner see Inferno test cases here:
https://github.com/infernojs/inferno/blob/master/packages/inferno-create-element/__tests__/components.spec.jsx#L2528-L3219

Hopefully you find good way to fix this :) So we can improve inferno too. Inferno currently updates vNode parents after setState to have this working + cloning vNodes before patching.. Which has obvious effect in performance