Bukkit

v1.1

Bugfix: \nick do not removed nickname
Add: \nick <a used nickname> tells who is using the nickname

v1.0

Deny duplicate nickname

Deny nicknames that equal a player name logged:
- Deny when a player wants to set a nickname which is another logged player's name (colored or not)
- Remove a player nickname (in nick.yml) when a player with the same name logs in

Rem: the comparison between nicknames uses nicknames without color codes