[ Sylvain Ferriol ]
  * add Test::Debconf::DbDriver::CommonTest::test_shutdown to verify sync of
    data between cache and file on shutdown.
  * add Test::Debconf::DbDriver::CommonTest::test_shutdown to verify sync of
    data between cache and ldap on shutdown.
  * add unit tests to validate debconf_copydb.
  * add Test::CopyDBTest::test_201431. Closes: #201431