Organized imports.
Zombie stuff is now handled by the map manager so that they are loaded when the map is changed.
Lights and stuff are now removed when changing maps. Still some bugs that need to be fixed though.
Fixed bug where the player wasn't put at the correct position when changing maps.
Shadows are no longer shown for the player and zombies - they looked weird as it's a top down game.
Merge branch 'wip'