OpenHAB ISY Binding rework

current status and problems

ISY bridge discovery

The binding currently doesn't support auto-discovery, although supported by the ISY after enabling UPNP in the network tab. It can be added manually, but that creates a slight problem since the binding assigns a unique ID (UID) that is generated, and not based on the UID of the actual device - thus multiple instances of the bridge could be added, which probably wind up stepping on each other.

FIX

regardless if auto-discovered or manually added, use the UID of the ISY to create the OHAB UID. This way, each unique device can only be added once