Implement .arena commands

add new commands to the core to handle with arena teams.

.arena create [player] "arena name" [type]
.arena create "arena name" [type]
.arena disband [TeamID]
.arena rename "oldName" "newName"
.arena captain [TeamID] [Player]
.arena info [TeamID]
.arena lookup [name]

note: the old PR closed cause the branch make me some problems with the merge after the pinfo command.