Adds stable trade and help commands, disables join and part commands due to bug

I added a working trade command and a help command that tells you what each command does and how to use it in typical IRC/command prompt style.  I disabled join and part commands because they have a tendency to freeze chat for some yet unknown reason.  Tidwell made an issue for this, and I commented with my findings on the issue there.  I also renamed the class APIComm to Player to make it more consistent with the other commands, and I was thinking about doing so with RoomComm too (ex: make a join class and a part class), though this policy could introduce unnecessary clutter if we take it too far.  I've tested the trade a help functions quite a bit myself and they seem to work just fine.  I copied a bit of code from icbat's work on a trade command, and though I changed it a lot and made it work, I thought I'd give him credit for the framework of it.  Last of all, I added format strings to every command class, they're used in the help command and eventually, every command should tell you if you format the command wrong.  Right now only some of them do.  Cheers :)