Store the dirmeta checksum instead of dirtree
Store the dirmeta checksum instead of dirtree

The metadata is the part we actually want. We don't really need the
dirtree object since we already have all of the files listed in the
mddb, and this is a lot easier than trying to get the dirmeta object
from a dirtree checksum.

dashea/bdcs,weldr/bdcs,dashea/bdcs,atodorov/bdcs