Error messages with portal SOAP services
SOAP service for getting error message does not work well (since SVN commit r2259) : it does not take care of language, and error code must be sent as first argument (unlike to wsdl).
Besides, SOAP authn failures' error messages displayed in login history are not really explicit : for example 'SOAP::Data=HASH(0x7f2d8e5cff70)', instead of 'Wrong credentials'. This is due to conversion of string error message into SOAP::Data object in LL::NG::Portal::Simple->error(). But this conversion is useless, since it is done in LL::NG::Common::CGI::SOAPService.