fixed screen flickering when switching inventory/ingame
add inventory background
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
revamped collision detection (now only in visible screen instead of all)
fixed bug inventory screen NullPointerException, when exiting without using inventory
restructure classes -> normal classes (helper) & manager (main classes)
add chest spawn
add chest collision
revamped inventoryscreen & inventory.png
revamped chest & chestmanager
add golden chest