Add local nameserver conf to VirtualBox scripts for dnsmasq
remove extra line
fix typo in address
exclude localhost as a valid nameserver
add 8.8.8.8 as backup nameserver just in case
simplify nameserver logic and use simple grep options
Merge pull request #1370 from Mirantis/add-local-dns-vbox

Add local nameserver conf to VirtualBox scripts for dnsmasq