This commit completes the previous commit so that both QString and
QStringBuilder now operate on UTF-8 input.
A small fix was required in QStringBuilder: an if clause isn't enough
to separate the two append versions. Since there are no QString
functions that append to char*, if we're converting to a QByteArray,
we need to go through a QString first in a separate function.
Change-Id: Ic503340c5d0c32d420c90c91cc2e0fc1ae9230f3
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>