Deleted unused method
Fixed typobug in Tile.getDistanceTo(x,y);
Tidied up code
Made object layer visible in map editor.
Created new map for testing out new AI feature.
Bomb now explode faster.

2 seconds (old: 3 seconds)
Created isEnemyOf(Creature) method.
Added an info comment to Creature.getNewMovementDestination().
isAnOKMoveDest doesn't check for visibility anymore.
Created Tile.isAnOKMoveDestinationFROM(x,y).
Deleted HandgunBullet class.

Because it’s no longer used.
Renamed controlled creature to NPC.
NPCs may now have WaitTasks up to 3 seconds.
Created AI.isAttacking() method.
Why was desktop/build ignored?
NPCs no more follow the player through lava.
Tidied up the AI code.
Refined Tile.isAnOKMoveDestinationFrom(x,y) method.