Added Animation and AnimationSprite classes from 
https://github.com/LaurentGomila/SFML/wiki/Source%3A-AnimatedSprite
Some small fixes and lots of new stuff in GameObject
AnimatedSprite/Animatiom.cpp/h: fixed includes
GameObject.cpp/h: Added functions to control animation and object type
GameItem.cpp/h: Created an empty class for GameItem which will be inhereted by GameCrystal and GameSpelbook