CollectionView viewComparator option for custom collection view sorting

See discussion here: https://github.com/marionettejs/backbone.marionette/issues/2056
Which logic?  The body of the `if (viewComparator)` section?  Just want to be sure I'm updating the same parts you are referring too.

This logic was ripped almost in full from Backbones sort logic, so that's why it's is just kind of thrown in here as a whole.