And to answer your question, no, I didn't alter resolvconf behavior when running 14.04. When forcing a "dpkg --configure -a", and then a "apt-get -f install", it seems to fix that problem and I have a properly running system.
I tried to upgrade another computer from 15.10 and didn't encounter that problem, I got systemd upgrade error BTW, but it was fixed by the automatic "dpkg --configure -a" run at the end.
And to answer your question, no, I didn't alter resolvconf behavior when running 14.04. When forcing a "dpkg --configure -a", and then a "apt-get -f install", it seems to fix that problem and I have a properly running system.
I tried to upgrade another computer from 15.10 and didn't encounter that problem, I got systemd upgrade error BTW, but it was fixed by the automatic "dpkg --configure -a" run at the end.