Git can tell you what the root dir of the repo is, so the scripts don't
need to force the user to cd there first.
Signed-off-by: Sebastian Kuzminsky <seb@highlab.com>
This commit does these things:
* Add a small shell library called githelper.sh, which reads a bunch
of info from git and makes it available as environment variables
in the caller.
* Add a script called version-is-release, which checks to see if
the current version (HEAD) has a signed release tag pointing to it.
* Update update-dch-from-git and get-version-from-git to use the
new githelper library, for consistency.
