Well, at least all virtual method overrides that I could find, there are probably more of them.

Also correct the few errors detected by this:
- KrViewer::windowActivationChange... this one existed in Qt 3 but not 4 or 5.
- Konfigurator::slotButtonClicked.. well, not fixed, just added a TODO comment, will be done when porting away from KDialog.
- KonfiguratorExtension::connectNotify... signature and implementation ported to Qt 5 now.
- KRQuery::(dis)connectNotify... signatures and implementations ported to Qt 5 now.