setup.sh: Point to the new homectl (hc)
hc init: Emit a different completion message after an upgrade

Users don't need to run deploy.sh since they are already deployed.  Emit
a different message reflecting that this was an upgrade instead of a new
setup.
Massive Documentation Update

- Use homectl 0.3 syntax (hc instead of homectl, etc.)
- Start on NEWS for 0.3
- Expand/discuss the anatomy of a homectl package