to disk changes

[Eric Dean Tribble <tribble>]

I just put up changes for the current version of snarfing-to-the-disk.
I managed to get the Hxx to compile, and there aren't too many errors
in the cxx.  Most subclasses of Shepherd won't compile for the moment
until we automatically generate the appropriate Locking and Stub
behavior.

The primary things left to do are:

Implement hash collision based forwarder resolution.
Dismantle forgotten objects when they come in from disk.
Remember a Forgotten flag for each snarf (if there are any forgotten
flocks).
Implement out-pointers in Snarfs.
Make everything actually compile.
change from a fluid Turtle to a fluid grandmap.

Michael and I also need at least on more pass resolving our protocol
differences (SnarfPacker isn't a subclass of CommHandler, for
instance).

See you after hackers.
dean