|SOURCE|
[Common::GameState]
* Moved the InputBinder and EventRouter from GameplayGameState into this class
  as derived classes will be using it as well
* GetEventRouter added to retrieve the event router associated with the derived
  state
[Common::GameStateManager]
* Added a GameStateInputListener which is added to the top-most state's event
  router, this is for listening for keyboard events
[Common::GameplayEvents]
* GameplayInputListener will respond to ActionInputEvents, re-interpreting them
  for gameplay
[Common::GameplayGameState]
* GameplayInputListener is added to the list of listeners for the event router
[Common::Game]
* Keyboard state is tracked and sent to the global event listener (which should
  be the top-most game state)