Use dnsmasq to reduce system hangs on dns-server downtime

We would like to use reduce system hangs on dns-server by using dnsmasq
as dns cache server. This was reported and tracked in bnc#901497
I've checked sources of `dnsmasq` and it has no limitation for number of nameservers. But recommended configuration is still to keep separate `resolv-dnsmasq.conf` file.