implement mana attributes, mana getters and #ManaTransform
implement adapters for mana objects
implement #manaTransform
implement #drawManaIndicator
set mana amount
Merge branch 'master' into magic

Conflicts:
	src/main/java/dungeon/game/GameLogic.java
	src/main/java/dungeon/models/Player.java
merge master
implement icebolt on k keypress
implement ice bolts
Add a basic inventory screen
Fix coding style
Make items usable from the inventory
Refactor GameLogic
Fix some bugs
Merge branch 'master' into magic
Merge branch 'magic'
Merge branch 'master' into inventory

Conflicts:
	src/main/java/dungeon/game/GameLogic.java
	src/main/java/dungeon/ui/screens/Canvas.java
Merge branch 'inventory'