* Add exceptions and outputs catching to multiprocessed routines.
* Change the output signature of `run_as_processes` to return a bool
  flag indicating success, and a list of routine-wise output value or
  RuntimeError (that may either result from an actual failure or from
  the process having been interrupted due to another one's failure).
* Add `auto_stop` parameter to enable disabling the default automated
  interruption of processes once any of them has failed.