- Removed EntitiesSet::draw() method.
- Added a drawAll() method in EntitiesManager and LightsManager.
- Now Scene::draw() method calls EntitiesManager::drawAll().
- Added a new AbstractEntitiesManager template class including a selectDrawableByRayPicking() method.
- Now LightsManager inherits from previous AbstractEntitiesManager class.
- Added a EntitiesSet::intersectsRay() method.