Update the scene when the molecule changes.
Update the scene when the molecule changes.

Change-Id: Ic174e4e058e28baa6828f84e53d8b9de9d49d3f8

OpenChemistry/avogadroapp,OpenChemistry/avogadroapp,OpenChemistry/avogadroapp,ghutchis/avogadroapp,wadejong/avogadroapp,ghutchis/avogadroapp,ghutchis/avogadroapp,OpenChemistry/avogadroapp,wadejong/avogadroapp,wadejong/avogadroapp,ghutchis/avogadroapp