BGE: Fix T48071: Global logic manager

Previously the logic manager was used as a global variable for SCA_ILogicBrick::m_sCurrentLogicManager,
this request to always update it before run any python script and allow call function like
ConvertPythonTo[GameObject/Mesh]. The bug showed in T48071 is that as exepted the global
m_sCurrentLogicManager is not updated with the proper scene logic manager.
Instead of trying to fix it by updating the logic manager everywhere and wait next bug report to add
a similar line. The following patch propose a different way:
- Every logic brick now contain its logic manager to SCA_ILogicBrick::m_logicManager, this value is
  set and get by SCA_ILogicBrick::[Set/Get]LogicManager, It's initialized from blender conversion and
  scene merging.
- Function ConvertPythonTo[GameObject/mesh] now take as first argument the logic manager to find name
  coresponding object or mesh. Only ConvertPythonToCamera doesn't do that because it uses the
  KX_Scene::FindCamera function.

Reviewers: moguri

Differential Revision: https://developer.blender.org/D1913

source/gameengine/Ketsji/KX_SCA_AddObjectActuator.cpp

@@ -216,7 +216,7 @@ int KX_SCA_AddObjectActuator::pyattr_set_object(void *self, const struct KX_PYAT
 	KX_SCA_AddObjectActuator* actuator = static_cast<KX_SCA_AddObjectActuator*>(self);
 	KX_GameObject *gameobj;
 		
-	if (!ConvertPythonToGameObject(value, &gameobj, true, "actuator.object = value: KX_SCA_AddObjectActuator"))
+	if (!ConvertPythonToGameObject(actuator->GetLogicManager(), value, &gameobj, true, "actuator.object = value: KX_SCA_AddObjectActuator"))
 		return PY_SET_ATTR_FAIL; // ConvertPythonToGameObject sets the error
 		
 	if (actuator->m_OriginalObject != NULL)