add option for deleting an alias to delete collections first

If someone wishes to delete an alias, it would be nice to have an option to delete the collections it points to as well. This would make deleting a Time Routed Alias much more user friendly. Given that in general, more than one alias might point to a target collection, it should only delete the collections that have only this alias pointing at them – no others. This way, the other aliases remain valid. Also, aliases can point to other aliases; I don't think this proposal here should apply recursively; it should only apply to the direct children that are collections.

Perhaps the option ought to be deleteCollections=true/false