Add option for verbose telnet negotiations

[DavidRieman]

It should be easy (perhaps via an app config option) to enable mode(s) which echo information about telnet negotiations. E.G. the client could receive a handful of outputs like (MCCP: on) or even more verbose versions for debugging. This could help prepare for #91. Beyond that, it could be helpful for users who know what it's about to see what is being negotiated during the start of the connection, while others will likely simply ignore such technobabble and start paying real attention at the splash screen.