adding working basis of nifty

modified:   src/game/Game.java
modified:   src/game/GameLoop.java
Merge branch 'master' into gui
Merge branch 'master' of https://github.com/Mathgoat/square-loot into gui

Conflicts:
	src/game/GameLoop.java
adding an enum representing every existing item

new file:   src/item/ItemListEnum.java
first version of the inventory handling
only the primary weapon is handled

modified:   src/entity/player/Player.java
modified:   src/game/Game.java
modified:   src/game/GameLoop.java
modified:   src/item/Battery.java
modified:   src/item/Equipment.java
modified:   src/item/Item.java
modified:   src/item/accessory/Accessory.java
modified:   src/item/motionGear/MotionGear.java
modified:   src/item/shield/Shield.java
modified:   src/item/weapon/LaserRifle.java
modified:   src/item/weapon/PrimaryWeapon.java
modified:   src/item/weapon/SecondaryWeapon.java
modified:   src/item/weapon/Weapon.java
new file:   src/userInterface/HUD.java
new file:   src/userInterface/UIController.java
modified:   src/userInterface/inventory/Inventory.java
handling the health bar

modified:   src/game/GameLoop.java
modified:   src/userInterface/HUD.java
further improvement of the gui, handling the four other equipments

modified:   src/userInterface/HUD.java
Energie overlay
moving the inventory from LivingEntity to Player

modified:   src/entity/EntityManager.java
modified:   src/entity/LivingEntity.java
modified:   src/entity/npc/Npc.java
modified:   src/entity/npc/Zombie.java
modified:   src/entity/player/Player.java
modified:   src/game/GameLoop.java
modified:   src/userInterface/OverlayManager.java
modified:   src/userInterface/inventory/Inventory.java
Merge branch 'master' into gui

Conflicts:
	src/game/GameLoop.java
	src/item/weapon/LaserRifle.java
	src/item/weapon/PrimaryWeapon.java
	src/item/weapon/SecondaryWeapon.java
	src/item/weapon/Weapon.java
	src/userInterface/inventory/Inventory.java
adding the Key item

new file:   assets/textures/key.png
modified:   src/item/Battery.java
modified:   src/item/ItemListEnum.java
new file:   src/item/Key.java
modified:   src/rendering/TextureManager.java