something closer to how we used to do it. The Lite2 way is to check the
"fsclean" flag in the superblock and stop there if so (during preen).
We now do the various superblock sanity checks that we used to do before
since it's cheap. We now get the filesystem state summary again instead
of "FILESYSTEM CLEAN; CHECKING SKIPPED" (or whatever).
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.
