Skeleton of a release script
Add version reporting to weaver
Up to the point of making a git release

(under my own account for the minute)
Better (working) way of checking for a release
Push tagged images to docker
prepare -> build to better avoid mistakes
Put versions in the script and weavedns too, and report them

    sudo weave version
Switch to proper github and dockerhub repo
Don't hardwire executable names; use logical names instead

We could use `os.Args[0]` instead of hardwired names, but that ends up
being e.g. `/home/weave/weaver`. So, use logical names instead.
Quote all echoings and be consistent about the message prefix
Do better with checking the changelog

Before, this could fail without a message if there was a changelog but
no matching line.

Also change the changelog format
      == Release v0.0.1
to
      == Release 0.0.1
cosmetic
No need for make publish
Missed change of command in usage message
Factor out ask_version and don't exit 1 if it fails
nicer error when there is no version tag
more idiomatic go build time variable setting
avoiding the use of 'sed'
accept lightweight tags
ignore release dir
don't allow lightweight tags after all