Supports the three coarse-grained placements we decided on:

  "SYSVOL" is special. You can declare a single blockstore with this
       placement and it will create a "native" (ufs/ext) filesystem on
       the 4th partition of the boot disk. This is how you create an
       extra storage partition that can be captured in a custom image.
       We don't use a volume manager here because imagezip doesn't
       recognize any of them (lvm, zfs, vinum).

  "ANY" coalesces all "available" storage from all disks into a logical
        volume manager pool and dishes out storage from that for
        individual blockstores. Typically this would include, the 4th
    partition of the boot disk (if not in use) and the second hard
    drive. If the machine has more than 2 drives, it will include
    all the extra drives.

  "NONSYSVOL" coalesces all "available" storage that is NOT on the
       boot disk into a logical volume manager pool and dishes out
       storage from that for individual blockstores. This case is if
       you want to avoid interfere with the system disk.

Only implemented on FreeBSD 8/9 with "vinum" right now. It only creates
"concat" (JBOD) volumes right now.

This stuff will probably get split out into its own perl module(s) at
some point, as it is getting large.

Next up is LVM on Linux and then maybe ZFS on Freebsd.