HelpCommand: Add class.
main: Use enum ‘Config::Command’.
ADirCommand: Rename method ‘createMarker’ to ‘createPlaceHolder’.
ADirCommand: Rename method ‘removeMarker’ to ‘deletePlaceHolder’.
DirDescriptor: Rename members.
Config: Fix ‘list’ command configuration.
Config,toString: Add ‘command’ output.
CleanCommand: Cleanup code.
Config,nameValueStr: Usse ‘auto’ keyword.
ADirCommand,deletePlaceHolder: Fix output for ‘short’ mode.