options `start' and `stop' now (unless I have forgotten any). This allows
us to call the scripts from /etc/rc.shutdown with the correct option.
The (42 or so) ports that already DTRT before are unchanged.
Some apps such as VMware for Linux would be happy with it.
The code was originally written by Vladimir N. Silyaev.
Note: It _includes_ Linux ioctl support, but basically it's
FreeBSD native stuff. I'm importing this into emulators
category for convevience' sake. Check it out.