Make it possible to claim usernames from nonactive turfers

[Tyger]

It should be possible to claim usernames from nonactive turfers. Of course there should be restrictions, before it would be possible to claim a username: i.e. the turfer hasn't logged on for a few years, the turfer isn't among the 1000 (or whatever number) first turfers on the total list, the turfer hasnt won a medal during a round or a bonanza, the turfer hasn't reached the rank (whatever) etc etc.