* plugin-runner.c (main): When a plugin is killed by a signal, show
                          the signal name, not just the number, in the
                          debug log message.

* plugins.d/password-prompt.c (termination_handler): Store received
                                                     signal in
                                                     "signal_received".
  (main): If exiting due to signal, re-raise signal received instead
          of returning.