Add fsctl command to summon reincarnation

If you start freeswitch with -reincarnate or -reincarnate-reexec, FS
will restart automatically in the event of an unexpected exit.

Currently, you can cause FS to immediately call exit(0) with `fsctl
shutdown now`, or you can have it call abort() with `fsctl crash`.
Which are both nice, but if you have reincarnation engaged, you really
might want FS to call exit([non-zero]) so the great supervisor
immediately breathes life back into your system.

This is now available via `fsctl shutdown reincarnate now`.

src/switch_core.c

@@ -2421,6 +2421,10 @@ SWITCH_DECLARE(int32_t) switch_core_session_ctl(switch_session_ctl_t cmd, void *
 		switch_console_save_history();
 		exit(0);
 		break;
+	case SCSC_REINCARNATE_NOW:
+		switch_console_save_history();
+		exit(SWITCH_STATUS_RESTART);
+		break;
 	case SCSC_SHUTDOWN_ELEGANT:
 	case SCSC_SHUTDOWN_ASAP:
 		{