all instances of `${CMD_OSTYPE}` to just using ${OSTYPE}. This saves us a
shell invocation on anything that is OS-dependent. I seriously doubt that we
will be spontaneously changing OS types during bootup.
xntpd_* -> ntpd_*
portmap_* -> rpcbind_*
Also change single_mountd_enable to mountd_enable.
We also include shims for all the old variable names.
Submitted by: Mike Makonnen <makonnen@pacbell.net>