Better failing than silently ignoring a missing parameter because of a
typo. Only parameters provided by users should be allowed to be missing,
not internal ones.

This value is used as a directory name, so we should follow the common
denominator.

Also, follow naming convention.

vincent: Minor fixes. Move branch switch to a separate commit.
vincent: Provide configuration to mysql_install_binary.

otherwise it will be invokec by supervisord.

with this, we can manually disable/enable a backend node so that we
can safely restart it.

because webrunner uses only one IPv4 local address.

Tests directory of inserted paths also needs to be in sys.path so that tests
can import other tests.

Tests directory of inserted paths also needs to be in sys.path so that tests
can import other tests.

because slapos.zcbworkarounds is a part of buildout extensions.

This reverts commit 061a05cd.

This reverts commit 4dba26ff.