The purpose of the added script is to shorten calling neoctl by removing the
need to constantly supply things SlapOS can provide on its own like
certificates and admin address. A sample command is now as simple as:

    ~/srv/runner/instance/slappartX/bin/neoctl set cluster STARTING_BACKUP

/reviewed-on !120

As `setuptools.archive_util.unpack_archive` (or self.extract
from slapos.recipe.build) is not able to handle .tar.xz archives,
tar component is added to wkhtmltopdf build dependencies.

As wkhtmltopdf sometimes needs to get files in
current working directory ONLY, this has to be
set correctly.

E.g. `wkhtmltopdf toc --xsl-style-sheet no_absolute_path.xsl input.html output.pdf`

After some upstream refactoring, a #include is missing (at least up to 2.3.14),
but still pulled implicitely when openssl is built with engines. This commit
fixes the configure step, so that HAVE_OPENSSL_ENGINE is true as expected.

More on https://community.openvpn.net/openvpn/ticket/792

/reviewed-on nexedi/slapos!122

This reverts commit 7f6729de.

ZODB has been switched to ZODB4 in 447b27e6 (Switch from ZODB3 (3.10.7)
to ZODB (4.4.4)) including raising transaction version requirement to
1.7.0 so we can try to introduce zodbtools one more time.

/proposed-for-review-on nexedi/slapos!121

Without it, the interest of tweaking the partition table is limited, because:
- it is impossible to free space efficiently
- 'optimize table' is even slower

slaprunner: export script shouldn't succeed if the backup of the contained instances are running at the same time

- version up: setuptools 30.1.0
- revert commit 1d0a8073

NEO is also not ready yet for transaction 2.x