BGE cleanup: KX_GameObject::GetParent() no longer increases the object's refcount.

I'm not sure why this function ever increased the object's refcount. Any
place in the code that calls KX_GameObject::GetParent() has to turn
around and call parent->Release(). Forgetting to call Release() was a
common cause of memory leaks (in fact, KX_SteeringActuator was probably
leaking). If the refcount needs to be increased, the calling code can
handle calling AddRef().

source/gameengine/Ketsji/KX_RaySensor.cpp

@@ -265,9 +265,6 @@ bool KX_RaySensor::Evaluate()
 	if (!spc && parent)
 		spc = parent->GetPhysicsController();
 	
-	if (parent)
-		parent->Release();
-	
 
 	PHY_IPhysicsEnvironment* physics_environment = this->m_scene->GetPhysicsEnvironment();