Ogre Instancing: Fix placeable to be set with instanced entities. Add more logic to the instance state objects in OgreWorld, including optimization runs after 5 seconds after creations/deletions have been done.
Ogre Instancing: Convert everything to use the OgreEntity() function instead of the deprecated GetEntity(). Check that all these places have proper null checking in preparation for instancing.
Ogre Instancing: While we are at it, fix all deprecated uses of GetBone() and GetAttachementEntity().