Updated code

Class was initialized (class 'ListPlayers') but never actually used.
Class now has an init field (__init), this code is executed when the
class is created.
A class variable has been created (chatColor), that can now easily be
changed to indicate the chat color.
Also optimizes ferformance by only having to create a color once.

Moved PlayerChat and list command event functions to the class.

Added a class initializer, so the class actually gets created, and the
initializer gets called.