Merge pull request #748 from marineam/core

systemd: enable capturing coredumps for inspection via coredumpctl
sys-apps/systemd: Remove default name servers
Merge pull request #749 from crawford/dns

sys-apps/systemd: Remove default name servers
systemd: slurp bugfixes in from master

This pulls in all patches marked with a Backport note as well as a some
assorted networkd fixes. May this release be a little less crashy...