handle lgc.adbh api changes within regards of backup/restore:
* new backup_commands method instead of backup_command
* some backend still return command as string as expected by os.system, not subprocess.call
"""Common subpackage of cubicweb : defines library functions used both on the
hg stserver side and on the client side
:organization: Logilab
:copyright: 2001-2010 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.
:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses
"""