XLINE [time] <gecos> :[reason]

[time] if present, gives number of minutes for XLINE

Adds a XLINE which will ban the specified gecos from
that server. The banned client will receive a message
saying he/she is banned with reason [reason]

XLINE [time] <gecos> ON irc.server :[reason]
will xline the gecos on irc.server if irc.server accepts
remote xlines.

- Requires Oper Priv: xline
