Checkpoint file to restart after crash

[rc83]

Sometimes the simulation crashes. It would be useful to restart the simulation just before the crash to quickly reproduce the conditions for debugging. Hence the simulation state shall be regularly output into a checkpoint file in the same way as it is written at the end of the simulation as a part of the analysis (SaveState).

Cmd line arguments: Number of macro MC steps between the checkpoint file updates.

[mlund]

Serialization libraries:

• https://github.com/USCiLab/cereal (easy POD to binary)
• https://github.com/felixguendling/cista

[mlund]

Related to #242