Add file server configuration and fix an IRC bug

Two things in this PR. One, I've added the configuration of a file server to share the CRL with the class off the classroom machine. The instructions I've written for the new Advanced capstone reference this.

Two, the advanced::irc::server class includes the irssi class, which is not what it seems to be called anymore. I've changed this to include advanced::irc::client, which does what I think we want it to.