FragmentedNuclei Bug

[ryanmrichard]

Based on an error I saw elsewhere, I am speculating that if the nuclei in the Nuclei object are identical (including coordinates) you can get FragmentedNuclei which are different to incorrectly compare equal. While one can argue about the physical meaningfulness of stacking atoms literally on top of each other, but it isn't the place of FragmentedNuclei to make that call. If FragmentedNuclei can distinguish among those atoms (which it can because it refers to them by index) then the instances should compare different.