Allows zeroconf to work also on ubuntu/linux in a network where there
is a local domain (like nokia).
This code is taken with as little changes as possible (to ease merge)
from apple mDNSResponder 320.5 (thus it does not respect Qt code guidelines)

Change-Id: Ic68ec3970ee9d6b02d2dc7cfb0ae1fbaf5a95bef
Reviewed-by: Christian Kandeler <christian.kandeler@nokia.com>