tidy Address helper functions,
make ordering of members consistent in allocate and claim,
make linter happier,
remove some unused items, and
update some comments
when granting a range that spans a token and inserting a new token, the
free space on the last token that we are handing over has to change.
Add unit test for this too.
Using the Ring CRDT and Weave gossip, provides an interface
for the weave script to allocate IP addresses in `weave run`,
`weave start` and `weave expose`.
See docs/ipam.md for implementation details, and site/features.md
for user-visible changes.
Bryan Boreham