Updated to use SceneGraph to store objects.

Added SceneGraph.{cpp|h} which handles storing objects in various
granularities to make things quicker. Includes some changes in
Objects.cpp and many changes in WorldManager to replace the use
of ObjectList updates with a scene graph. In the process of debugging
I added some logs for starting up managers (before it was only on
errors) which I'm leaving. Also fixed a bug in GameManager.cpp where
the value for fflush was not passed along if you called the startUp
function that only took fflush.