This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
preen (-p), and in that case the filesystem is skipped if it is clean.
A new flag "-f" for 'force' has been added which basically gives back
the old behavior of checking all the filesystems all the time. This
very closely models the behavior of SunOS and Ultrix.
