Rework auth.ldap logging

Signed-off-by: Etienne CHAMPETIER <etienne.champetier@fiducial.net>
Correct all 'AJXP_Logger::logAction("error"'

Signed-off-by: Etienne CHAMPETIER <etienne.champetier@fiducial.net>
Add prefix (class name or plugin id) to debug log

Signed-off-by: Etienne CHAMPETIER <etienne.champetier@fiducial.net>