Allow sorting species list by count

[kazlauskis]

Steve Blain:
Another suggestion. In the listing functions you have the very handy filter option, which cycles between order entered and alphabetical. How about a third option here: numeric - so the highest counts at the top of the list (or the opposite way round as well) - this would make adding more individuals of the most numerous species easy if you have a long list as they would be at the top.