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### Issue description
The datadir field on the debug window displays incorrectly if the profile folder name is accented.

### How to reproduce
1. Create a profile with accented profile folder name (àèìòùáéíóú)
2. Run bitcoin core with the default datadir
3. Go to the debug window and look at the datadir field

### Expected behaviour
The datadir folder path should display correctly.

### Actual behaviour
Accented characters display as a unknown character question mark.

### Screenshots
![Debug Window](https://cloud.githubusercontent.com/assets/11365204/20029647/41dee90e-a352-11e6-8784-e5a48798d62e.png)


### Confirmed affected versions
The bug has been tested on the following implementations:

- v0.13.1 from source cross-compiled for Windows x64 on a Ubuntu 14.04 enviroment
- 0.13.0 official Windows x64 binary

### Additional debug info
Copying and pasting the text into a program that is known to support accented characters (Such as Notepad++) still displays unknown character symbols.
PaymentRequestPlus request;
        SendCoinsRecipient recipient;
        if (!request.parse(data))
        {
            qWarning() << "PaymentServer::netRequestFinished: Error parsing payment request";
            Q_EMIT message(tr("Payment request error"),
                tr("Payment request cannot be parsed!"),
                CClientUIInterface::MSG_ERROR);
        }
        else if (processPaymentRequest(request, recipient))
            Q_EMIT receivedPaymentRequest(recipient);
        return;
    }
    else if (requestType == BIP70_MESSAGE_PAYMENTACK)
    {
        payments::PaymentACK paymentACK;
        if (!paymentACK.ParseFromArray(data.data(), data.size()))
        {
            QString msg = tr("Bad response from server %1")
                .arg(reply->request().url().toString());
            qWarning() << "PaymentServer::netRequestFinished: " << msg;
            Q_EMIT message(tr("Payment request error"), msg, CClientUIInterface::MSG_ERROR);
        }
        else
        {
            Q_EMIT receivedPaymentACK(GUIUtil::HtmlEscape(paymentACK.memo()));
        }
    }
}
void PaymentServer::reportSslErrors(QNetworkReply* reply, const QList<QSslError> &errs)