Minimal init

This is an updated, nommu-compatible version of my minimal init, adapted from the version originally published on ewontfix.com.

All it does it run /etc/rc on startup and reap orhaned processes as they exit. It does not do any process supervision.

The respawn utility also included is a minimal process supervisor. It's not intended for any elaborate supervision, mainly running gettys for login, started from /etc/rc in place of a traditional inittab. The entire command line argv[1] to argv[argc] is the command that is executed repeatedly, so argv[1] should be an absolute pathname. Bad Things will happen if it's a program which daemonizes itself.