SPIGOT-3607: Bad yaw from armorstands treated as living

nms-patches/EntityArmorStand.patch

@@ -122,3 +122,15 @@
          this.die();
      }
  
+@@ -733,4 +763,11 @@
+     public boolean cS() {
+         return false;
+     }
++
++    // CraftBukkit start - SPIGOT-3607
++    @Override
++    public float getHeadRotation() {
++        return this.yaw;
++    }
++    // CraftBukkit end
+ }