this fleshes out hostuuid better..
add a more useful debug print..

If the identity changed, generate a new uuid, and set created_by and
modified appropriately...

the modified is the correct, not mtime, as someone can put an
"older" modified file, but at a later time, so it's assumed
that the most recently modified fileobject has the most up to
date data..

The later happens after importing a container.

fix up code to pass all the tests...

This was partial work to go to python3, but I've now since learned that
going twisted is not the way I want to work for web frameworks, so a
large amount of this code will be dropped (kleintest.py) or rewritten..

as part of this work, also uplifted automatic promotion of uuid
to a UUID object...

add encode/decode methods to MDBase to make things more simple
when handling serialization...

add new_version that creates a new version with modifications

private members...  also increase coverage back to 100%, delete
outdated comments..

this involved restructing the objectstore to be more of a complete
repo, keeping things like create_by_ref for new objects...