…ases

This replaces the old do_release.pl, and works with the .dat files that
stage-release.sh produces to get all the information necessary.

By design, this script only handles one type of staged releases per run;
'public', 'premium' and 'security' are staged release types, and they affect
the staging repository that's used.  Upload locations / repositories are
determined from the version number of each staged release, unless given on
the command line.

Any set of release files that don't fit the chosen staged release type will
simply be ignored.

The following updates are performed:

- the source repository is updated with release commits and tag
- a github release is created in the appropriate repository
- the release files are copied to the appropriate file service directory
- omc/data is updated with added lines in newsflash.txt

The extra work surrounding security advisories is not performed by this
script at this stage.  That's left for later development.

This also updates release-tools/stage-release.sh to add version information
to the metadata file that release-tools/publish-release.sh can depend on.

…ables

This makes it possible to setup a test environment for staging and publishing.

This also modifies stage-release.sh's option --staging-address to
--staging-location, to reflect that it may also be a local directory.

This was useful once, but isn't any more.  Setting appropriate environment
variables has the same effect, and is easier to handle.

Signing of release files and tags is now only done if it hasn't been done
by stage-release.sh.

… and 'security'

Having the staging types 'public', 'premium' and 'security' was nonsense,
we don't really have that sort of division.  'ordinary' and 'security'
staging makes more sense for what we do, and that leaves it to the script
to fully determine for each version being released if it should become a
public or a premium release.

gpg is very annoying with how it prompts for pass phrases.  However, it's
possible to tell it to use the terminal with '--pinentry-mode loopback'.
In turn, git is annoying with how one can't specify gpg options directly;
instead, a small script that does the right thing is produced, and passed
to git with the gpg.program config option.

…ed releases