ubuntu 14.04 pptp client resolv.conf NetworkManager.conf DNS routing after PPTP connection
http://askubuntu.com/questions/640172/dns-routing-after-pptp-connection
http://www.stgraber.org/2012/02/24/dns-in-ubuntu-12-04/
askubuntu.com/questions/137037/networkmanager-not-populating-resolv-conf