UPBGE: Remove blender group object in KX_GameObject.

The blender group object member in KX_GameObject (m_blenderGroupObject)
was a redundant information has it is similar to
m_dupliGroupObject->GetBlenderObject().

This member is removed and its usage is replaced by calling function
GetBlenderObject of the dupli game object.

source/gameengine/Ketsji/KX_GameObject.cpp

@@ -111,7 +111,6 @@ KX_GameObject::KX_GameObject(
       m_currentLodLevel(0),
       m_meshUser(nullptr),
       m_blenderObject(nullptr),
-      m_blenderGroupObject(nullptr),
       m_bIsNegativeScaling(false),
       m_objectColor(mt::one4),
       m_bVisible(true),

source/gameengine/Ketsji/KX_GameObject.h

@@ -109,7 +109,6 @@ class KX_GameObject : public SCA_IObject, public mt::SimdClassAllocator
 	short								m_currentLodLevel;
 	RAS_MeshUser						*m_meshUser;
 	struct Object*						m_blenderObject;
-	struct Object*						m_blenderGroupObject;
 
 	bool								m_bIsNegativeScaling;
 	mt::vec4							m_objectColor;
@@ -548,16 +547,6 @@ class KX_GameObject : public SCA_IObject, public mt::SimdClassAllocator
 		m_blenderObject = obj;
 	}
 
-	struct Object* GetBlenderGroupObject( )
-	{
-		return m_blenderGroupObject;
-	}
-
-	void SetBlenderGroupObject(struct Object* obj)
-	{
-		m_blenderGroupObject = obj;
-	}
-
 	bool IsDupliGroup()
 	{ 
 		return (m_blenderObject &&

source/gameengine/Ketsji/KX_Scene.cpp

@@ -716,8 +716,6 @@ void KX_Scene::DupliGroupRecurse(KX_GameObject *groupobj, int level)
 			continue;
 		}
 
-		gameobj->SetBlenderGroupObject(blgroupobj);
-
 		if ((blenderobj->lay & group->layer) == 0) {
 			// Object is not visible in the 3D view, will not be instantiated.
 			continue;
@@ -739,8 +737,15 @@ void KX_Scene::DupliGroupRecurse(KX_GameObject *groupobj, int level)
 		// Add to 'rootparent' list (this is the list of top hierarchy objects, updated each frame).
 		m_parentlist->Add(CM_AddRef(replica));
 
+		/* Set references for dupli-group
+		 * groupobj holds a list of all objects, that belongs to this group. */
+		groupobj->AddInstanceObjects(replica);
+
+		// Every object gets the reference to its dupli-group object.
+		replica->SetDupliGroupObject(groupobj);
+
 		// Recurse replication into children nodes.
-		const NodeList children = gameobj->GetSGNode()->GetSGChildren();
+		const NodeList& children = gameobj->GetSGNode()->GetSGChildren();
 
 		replica->GetSGNode()->ClearSGChildren();
 		for (SG_Node *orgnode : children) {
@@ -808,15 +813,6 @@ void KX_Scene::DupliGroupRecurse(KX_GameObject *groupobj, int level)
 			// Can't instantiate group immediately as it destroys m_logicHierarchicalGameObjects.
 			duplilist.push_back(gameobj);
 		}
-
-		if (gameobj->GetBlenderGroupObject() == blgroupobj) {
-			/* Set references for dupli-group
-			 * groupobj holds a list of all objects, that belongs to this group. */
-			groupobj->AddInstanceObjects(gameobj);
-
-			// Every object gets the reference to its dupli-group object.
-			gameobj->SetDupliGroupObject(groupobj);
-		}
 	}
 
 	for (KX_GameObject *gameobj : duplilist) {

source/gameengine/Rasterizer/RAS_OpenGLRasterizer/RAS_OpenGLLight.cpp

@@ -154,7 +154,9 @@ GPULamp *RAS_OpenGLLight::GetGPULamp()
 {
 	KX_LightObject *kxlight = (KX_LightObject *)m_light;
 
-	return GPU_lamp_from_blender(kxlight->GetScene()->GetBlenderScene(), kxlight->GetBlenderObject(), kxlight->GetBlenderGroupObject());
+	KX_GameObject *groupObj = kxlight->GetDupliGroupObject();
+	Object *blenderGroup = groupObj ? groupObj->GetBlenderObject() : nullptr;
+	return GPU_lamp_from_blender(kxlight->GetScene()->GetBlenderScene(), kxlight->GetBlenderObject(), blenderGroup);
 }
 
 bool RAS_OpenGLLight::HasShadowBuffer()