Add a possibility to duplicate (deep clone) a Session

[Smurf-IV]

A situation has arisen where I have a need to calculate a set of facts down to a certain level (i.e. facts are missing thus preventing further rules from firing).
I then need to take a snapshot of the facts and create a new session, add some new facts for new objects, and run the new session again.

As the depth of the facts progress, then the number of facts and rules that are being exercised increases, thus if I have from the above a number of items requiring a common base at a level 5 iteration (number is just for demonstration) and I need to run this level a 1000 times against additional facts, this overhead of just setting up the level 5 becomes onerous.

What would be be great is for a level 5 session to be duplicated (deep clone) so that all previous conditions that have been set in the Rete tree etc are kept and thus do not need to be retested, and only the new facts and hence the unused rules need to be tested and "fired".