SHEDDING <server> <rate> :<reason>
SHEDDING <server> OFF

Turns user shedding on or off on the specified server. When a server is
shedding, a client will be disconnected from the server at a time period
defined by rate, until shedding is turned off. Clients with kline_exempt
are never affected by this feature.

- Requires Oper Priv: oper:shedding