Numerous fixes to vnode code based on testing.
Create a modest partition 4 (1G) since we need some space for local FSes. Rename many of the LVM routines to follow a common naming scheme. Make extra effort to remove partitions on an LV; something about a FreeBSD VM makes kpartx forget one of its partitions. Handle deltas on whole-disk images; some code was missing for this case. Make sure multi-image case works; the golden images was being named incorrectly. Make sure extra FS case works; for the golden image case we were using the golden image and ignoring what was specified for the extra FS.