Don't throw away multiple values per key when doing deep copy.

See http://reviewboard.kde.org/r/4235/


svn path=/trunk/KDE/kdelibs/; revision=1134838

datacontainer.cpp

@@ -50,7 +50,7 @@ void DataContainer::setData(const QString &key, const QVariant &value)
     if (!value.isValid()) {
         d->data.remove(key);
     } else {
-        d->data[key] = value;
+        d->data.insertMulti(key, value);
     }
 
     d->dirty = true;