Resolve device type ambiguity

[tecimovic]

Device types don't have a unique ID anywhere in the XML files, so they are ambiguous across multiple-spec versions of XML file.
It's a real problem when loading two separate specs of the XML file that contain same devices.

There is no single identifier to disambiguate.

[tecimovic]

I notice that when I save out an LO ON/off Light that gets loaded back in as a ZLL Dimmable Light. These device types are not unique so we have to be careful to match them to the device type name or something else that is unique.