devtools: Fix cleanup of temporary database (closes #1908656) The stored database path for clean up was not absolute. We now make the ``db-name`` absolute at database manade initialization. before storing the name for cleanup.

from os.path import join
from cubicweb.toolsutils import create_dir

option_renamed('pyro-application-id', 'pyro-instance-id')

create_dir(join(config.appdatahome, 'backup'))