Added a class that implements the IReconstructionContext interface.  Currently, class is very dumb: holds everything in memory and may do lots of duplicate work.
Simplifying map constructor order --- no longer have separate init_multithreaded_map_container call.  Goal is to move serialize_contents into init calls of AtomicObject.
Simplified nonatomic internal map constructor so avoid initialization.
Simplified internal list constructors.  Eventually want to get to point that all objects save their contents in initializers of AtomicObject.