Binding for Anel NET-PwrCtrl devices

A new binding for network-controlled power sockets from Anel-Elektronik.
@teichsta your comment still causes confusion to me because the KNX binding does it the very same way as I initially implemented it: https://github.com/openhab/openhab/blob/master/bundles/binding/org.openhab.binding.knx/src/main/java/org/openhab/binding/knx/internal/bus/KNXBinding.java#L111
Both receive-methods (for commands AND status updates) delegate to the same writeToKNX method. Shouldn't it be fixed there, too?