Makes many changes. It makes the sokoban_editor.rb and game.rb a singleton methods for the Sokoban module. It adds another game.rb and editor.rb in bin folder. From there a level must be played or built. It adds many function for the player move in game.rb and renderers.rb. The game can simply be played now in ShoesGUI or Console mode. Almost done for stable release, just need to add a few more tests and its OK!