2012-05-01 Kazuhiko
* use prefered_sender_section for credential related messages if exist.

2012-04-27 Kazuhiko
* use document_reference in Credential Recovery as the reference of nofitication message if exists.

2010-05-27 fabien
* implement Credential Request, add class, improve forms, ...
* Rename credential_question base category to question and add sub categories.