I've added an installation from optical disk drive facility. This enables FreeBSD to be installed from an optical disk, which may be formatted in "super floppy" style or sliced into MSDOS-FS and UFS partitions. Note: ncr.c should be reviewed by Stefan Esser <se@freebsd.org> and cd.c by Joerg Wunsch <joerg@freebsd.org> before bringing this into 2.2. Submitted-By: Shunsuke Akiyama <akiyama@kme.mei.co.jp>