Function: erc-identd-start

Start an identd server listening to port 8113.
Port 113 (auth) will need to be redirected to port 8113 on your
machine -- using iptables, or a program like redir which can be
run from inetd. The idea is to provide a simple identd server
when you need one, without having to install one globally on your
(fn &optional PORT)