add(sys-apps/systemd-sysv-util): Bump to version 207

As of 207 the systemd binary is only located at
/usr/lib/systemd/systemd, not /usr/bin/systemd. Fix the broken init link
accordingly, also add version to systemd dependency for good measure.
bump(coreos-base/coreos-init): Update to remove old getty generator.
bump(coreos-base/coreos-init): Update merge commit hash
Merge pull request #220 from marineam/systemd

Systemd