a few small thing discovery fixes

Signed-off-by: Kai Kreuzer <kai@openhab.org>
Instead of changing the state to OFFLINE by default i would like to introduce at least one state like "NOT_INITIALIZED" (or something similar), that is the default state for a thing when no handler is assigned. Because otherwise you could not distinguish between the two situations, when there is no binding for the thing, or the handler is already assigned, but did not yet set the status to ONLINE.