Port and update the Konqueror core (client, libkonq, src)

Note that this change must be applied after all of the others
that remove KDELibs4Support, otherwise the build will fail.

kDebug(), qDebug() -> qCDebug() with logging category
No need to link with KDELibs4Support
QDrag::start() -> QDrag::exec() with explicit argument
Window title and action icon for "Configure Extensions"