- kill only when returncode is none
 - to not play with hiding exceptions during runtime, so
   CertificateGenerationError, as simple ValueError is acceptable for
   simplicity
 - during revoking generate hashed links to the newest CRL


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@42381 20353a03-c40f-0410-a6d1-a30d3c3de9de