Added 'ExEchoGroupChanges'

It'll print off if a rank has been deleted or updated to the chat.
However, the way that Exsto handles rank updates is live, so you'll spam
your chat.  It's disabled by default, it's only a feature request.
Satisfies #96
Fixed a HUGE bug.  Surprised nobody caught this.

If using the group editor, and someone was editing ranks while you were
editing ranks before, opening the menu again would result in the first
persons changes not being applied, and yours updating over it.