Ability to restart from state point. Works in serial.

src/fixed_source.F90

@@ -34,6 +34,12 @@ contains
     ! LOOP OVER BATCHES
     BATCH_LOOP: do current_batch = 1, n_batches
 
+       ! In a restart run, skip any batches that have already been simulated
+       if (restart_run .and. current_batch <= restart_batch) then
+          if (current_batch > n_inactive) n_realizations = n_realizations + 1
+          cycle BATCH_LOOP
+       end if
+
        call initialize_batch()
 
        ! Start timer for transport