the new disk. This requires my previous changes to sgivol to get a non-
interactive mode. While here, change the way sysinst invoked sgivol (it
called system(), now it uses run_prog()) so we don't mess up the logging
and scripting contexts.
directory; the ramdisk build also relies on the termcap entry here, so this
isn't totally useless. All based on work by Scott Taylor (sgimips at
mrynet.com), with bugs most likely added by me.