Remove static instance creation of main class. The only reason a static
instance was being called was to easily provide a plugin instance to the
main class. What I should have done is not been lazy to begin with and
properly pass through an instance of KotH.java. So, to accomodate this
in a way that will not break API nearly as much, Messenger class now
utilizes JavaPlugin#getPlugin(Class <? extends JavaPlugin>);