Initial configd for python client

The wallaby-classic configd worked directly over QMF.
Since this is no longer possible, we are porting the
configd to the Wallaroo client library.  This file
represents a first pass at so doing.
Improved client/API support for Node attributes.

Python node-client objects now support a last_updated_version
attribute.  The identity_group attribute now returns a reference
to the identity group object instead of the name of the identity
group.
Fixes from the previous commit for Ruby.
Added missing snapshot functionality to py client
Node configs now include W_C_V
configd.py updated for wallaroo
Initial add of wallaby-classic shell commands.

If we want to keep the history behind these, we can
graft it in to the repository later -- these are pristine
copies from the current wallaby master.
removed commands that will not be in wallaroo
Initial, coarse changes to shell.
Smoke-tested shell running against Wallaroo.

NB:  fairly smoky.
untested fixes for cmd_relationship
wallaby-load smoke-tested
removed some spurious logging
logging tree splits
Proxying#exists? now handles non-404 error cases
Fixes for lambda-related time travel
subsystem properly includes arcutils
Fixes miscellaneous REST interface problems
Merge branch 'feature/basictools' into develop
Merge branch 'feature/shell-port' into develop