Enhancement: Simulation checkpointing

[mpoquet]

It would be very nice to have some kind of checkpointing mechanism in Batsim, so long simulations could be stopped and resumed.

[mpoquet]

This could be achieved by using DMTCP on a simulation instance manager (e.g., robin).

It may work directly or DMTCP plugins might be needed. Such plugins allow to define how to checkpoint or restart specific parts (ZMQ?).