Fix setting entity's target. Fixes BUKKIT-1358

Setting the goal target overrides the entity's will to do something
else. This makes it so entities like wolves with attack another player
with .setTarget(), instead of hanging next to their owner.

src/main/java/org/bukkit/craftbukkit/entity/CraftCreature.java

@@ -15,9 +15,11 @@ public class CraftCreature extends CraftLivingEntity implements Creature {
         EntityCreature entity = getHandle();
         if (target == null) {
             entity.target = null;
+            entity.setGoalTarget(null);
         } else if (target instanceof CraftLivingEntity) {
             entity.target = ((CraftLivingEntity) target).getHandle();
             entity.pathEntity = entity.world.findPath(entity, entity.target, 16.0F, true, false, false, true);
+            entity.setGoalTarget(((CraftLivingEntity) target).getHandle());
         }
     }