Add UFS snapshot[/shadow copy] support
autosnap.py currently supports ZFS only, but it shouldn't be too hard to retrofit it to use UFS as well.
Similarly, it looks like shadow copy support can be relatively painlessly achieved with UFS snapshots r1.
Work should be done to ensure that things function and are robust because the ticket creator hasn't actively used this support. Also, snapshotting with UFS needs work in [[FreeBSD]] 9.x (as delphij probably knows) when SUJ is enabled. There are reports of UFS causing system instability around the time that 9.0 was released r2.