Added Idle AI (default AI)

Added Idle AI (default AI) -- does nothing
Changed default angle for entities to align with correct default direction

core/src/gdx/diablo/ai/AI.java

@@ -3,6 +3,7 @@ package gdx.diablo.ai;
 import gdx.diablo.entity.Monster;
 
 public abstract class AI {
+  public static final AI IDLE = new Idle();
 
   protected Monster entity;
 

core/src/gdx/diablo/ai/Idle.java

@@ -0,0 +1,10 @@
+package gdx.diablo.ai;
+
+public class Idle extends AI {
+  public Idle() {
+    super(null);
+  }
+
+  @Override
+  public void update(float delta) {}
+}

core/src/gdx/diablo/entity/Entity.java

@@ -127,7 +127,7 @@ public class Entity {
   String  weaponClass;
   Vector3 position = new Vector3();
   Vector3 velocity = new Vector3();
-  float   angle    = MathUtils.PI * 3 / 2;
+  float   angle    = MathUtils.atan2(-1, -2);//MathUtils.PI * 3 / 2;
 
   boolean running   = false;
   float   walkSpeed = 6;
@@ -529,4 +529,6 @@ public class Entity {
   public String getName() {
     return name;
   }
+
+  public void select(Player player) {}
 }

core/src/gdx/diablo/entity/Monster.java

@@ -60,7 +60,9 @@ public class Monster extends Entity {
     //if (!object.Draw) return null; // TODO: Not yet
 
     Monster monster = new Monster(map, obj, monstats);
-    if (monstats.AI.equalsIgnoreCase("Npc")) {
+    if (monstats.AI.equalsIgnoreCase("Idle")) {
+      monster.ai = AI.IDLE;
+    } else if (monstats.AI.equalsIgnoreCase("Npc")) {
       monster.ai = new Npc(monster);
     }