I’ve disliked the NetworkManager dnsmasq integration for some time. As far as I understand it has caching turned off by default so I’m not sure what the rationale is at all. So disabling means 1 less system process and less magic on the system (since resolv.conf will reflect the actual nameserver settings rather than be overwritten by NetworkManager). The key to disabling this is to open:

/etc/NetworkManager/NetworkManager.conf

Comment or remove the line:

dns=dnsmasq

Then running:

sudo /etc/init.d/network-manager restart

And maybe:

sudo killall dnsmasq

Done.