#6 Save graph state

[Brendan Cleary]

Implement a save state capability that saves the
position and orientation of all root nodes in the graph
to a file on receipt of a request from a client
application. This file can be specified along with a
data source at run time to restore a graphs nodes to
the positions they occupied prior to the client
application requesting the persistence of the graph
nodes positions. To accomplish this will require the
provision of an interface to allow clients request that
node positions be persisted to a given file. We will
also be likely required to do a traversal of the graphs
parent nodes to accumulate the required position and
orientation information.