Develop and implement logic for reconfiguration of timeslices

Upon convergence, a timeslice object should be reconfigured to iterate on a later timeslice. Need to modify
- start time
- end time
- initial value
- neighbours
- reset residual and iteration counter

For now, do not consider the case where e.g. different time steps are to be used. The reconfiguration should avoid reallocating buffers for the solution?
