[qmf] Make SMTP AUTH PLAIN more robust.

SMTP authentication using AUTH PLAIN supports two ways to send the information to the server,
seems that some servers don't support anymore auth in two steps:

c: AUTH PLAIN
S: 334
C: <UserName and password encoded in base64>
S: 235 2.7.0 Authentication successful

Auth in one step introduced by this commit, better to reduce communication with the server

c: AUTH PLAIN <UserName and password encoded in base64>
S: 235 2.7.0 Authentication successful

qmf/src/plugins/messageservices/smtp/smtpauthenticator.cpp

@@ -63,10 +63,10 @@ QByteArray SmtpAuthenticator::getAuthentication(const QMailAccountConfiguration:
     SmtpConfiguration smtpCfg(svcCfg);
     if (smtpCfg.smtpAuthentication() != SmtpConfiguration::Auth_NONE) {
         QMailAccountId id(smtpCfg.id());
-        QByteArray username(smtpCfg.smtpUsername().toLatin1());
+        QByteArray username(smtpCfg.smtpUsername().toUtf8());
         QByteArray pass;
         if (ssoLogin.isEmpty()) {
-            pass = smtpCfg.smtpPassword().toLatin1();
+            pass = smtpCfg.smtpPassword().toUtf8();
             qMailLog(SMTP) << Q_FUNC_INFO << "SSO identity is not found for account id: "<< id
                            << ", using password from accounts configuration";
         } else {
@@ -80,7 +80,7 @@ QByteArray SmtpAuthenticator::getAuthentication(const QMailAccountConfiguration:
             result = QByteArray("LOGIN");
             gResponses[id] = (QList<QByteArray>() << username << pass);
         } else if (smtpCfg.smtpAuthentication() == SmtpConfiguration::Auth_PLAIN) {
-            result = QByteArray("PLAIN");
+            result = QByteArray("PLAIN ") + QByteArray(username + '\0' + username + '\0' + pass).toBase64();
             gResponses[id] = (QList<QByteArray>() << QByteArray(username + '\0' + username + '\0' + pass));
         }
     }
@@ -123,8 +123,8 @@ QByteArray SmtpAuthenticator::getAuthentication(const QMailAccountConfiguration:
     SmtpConfiguration smtpCfg(svcCfg);
     if (smtpCfg.smtpAuthentication() != SmtpConfiguration::Auth_NONE) {
         QMailAccountId id(smtpCfg.id());
-        QByteArray username(smtpCfg.smtpUsername().toLatin1());
-        QByteArray password(smtpCfg.smtpPassword().toLatin1());
+        QByteArray username(smtpCfg.smtpUsername().toUtf8());
+        QByteArray password(smtpCfg.smtpPassword().toUtf8());
 
         if (smtpCfg.smtpAuthentication() == SmtpConfiguration::Auth_LOGIN) {
             result = QByteArray("LOGIN");

qmf/src/plugins/ssoauth/password/passwordplugin.cpp

@@ -121,15 +121,15 @@ QList<QByteArray> SSOPasswordPlugin::getSMTPAuthentication(const QString &passwo
                                                     const QString &username, int serviceAuthentication) const
 {
     QList<QByteArray> result;
-    QByteArray user(username.toLatin1());
-    QByteArray pass(password.toLatin1());
+    QByteArray user(username.toUtf8());
+    QByteArray pass(password.toUtf8());
 
     if (serviceAuthentication == QMail::LoginMechanism) {
         result.append(QByteArray("AUTH LOGIN"));
         result.append(QByteArray(user));
         result.append(QByteArray(pass));
     } else if (serviceAuthentication == QMail::PlainMechanism) {
-        result.append(QByteArray("AUTH PLAIN"));
+        result.append(QByteArray("AUTH PLAIN ") + QByteArray(user + '\0' + user + '\0' + pass).toBase64());
         result.append(QByteArray(user + '\0' + user + '\0' + pass));
     } else if (serviceAuthentication == QMail::CramMd5Mechanism) {
         result.append(QByteArray(pass));