Allow sorting of skins by popularity

[Leonartist]

I don't think this would be a good idea. We would need a way to prevent players from
rapidly pressing the f5 button, or clicking the 'use skin button'. If we had the catolouge
list the most popular skins, the skins would tend to stay popular forever, never allowing
newer skins to have a chance.

I suggest we should have tags or keywords so people could find skins by subject. This
would produce more search results. (Maybe this can be added to games too.)