Added script to extend (or reconstruct) epoch trajectories
Added script to extend (or reconstruct) epoch trajectories

It permits to sort of extensions:
The reconstruction adding up to the last "lagtime" snapshots of a trajectory
The full reconstruction, tracing back to the first epoch

AdaptivePELE/AdaptivePELE,AdaptivePELE/AdaptivePELE,AdaptivePELE/AdaptivePELE,AdaptivePELE/AdaptivePELE