CommandList class erstellt
CommandShow class erstellt
CommandEcho class erstellt
CommandNext class erstellt
All Commands (echo, show, next, list, quit) implemented.

ToDo:
- Exceptions:
	+ Bad Alloc_Exception
		Game::addTower(...)
		Game::addMonster(...)
	+ Out Of Range:
		Game::splitInput(...)
		...
	+ ...

- Coding Standard
- Function Description Headers
- Error Cases and Return values of functions