add BigRockNPC and IronDoorObj; update AssetSetter to include new NPC and interactive tiles

src/de/miaurizius/jgame2d/entity/Entity.java

@@ -32,6 +32,7 @@ public class Entity {
     public int solidAreaDefaultX,  solidAreaDefaultY;
     public boolean collision;
     public String[][] dialogue = new String[20][20];
+    public Entity linkedEntity;
 
     // STATE
     public int worldX, worldY;
@@ -206,6 +207,7 @@ public class Entity {
 
     // INTERACTION
     public void setAction() {}
+    public void move(Direction direction) {}
     public void damageReaction() {}
     public void attacking() {
         if(panel.player.attackCancel && type == EntityType.PLAYER) return;
@@ -470,6 +472,7 @@ public class Entity {
         }
         return null;
     }
+    public void setDialogue() {}
     public void changeOpacity(Graphics2D graphics2d, float opacity) {
         graphics2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, opacity));
     }