Comment 76 for bug 1754671

I've reworked a bit the branch. The main change is a new
ipv{4,6}.dns-default property that replaces the "~." domain of the
previous version.

I've also written a short description of the changes at:

https://wiki.gnome.org/Projects/NetworkManager/DNS

Please have a look at branch bg/dns-domains-bgo746422.