churn(coreos-base/coreos-cloudinit): Move units into cloudinit repo.
bump(coreos-base/coreos-init): Deprecate old addon units.
fix(coreos-base/oem-rackspace): Rely on generic configdrive units.

Config drive is now supported on all VM platforms so it doesn't need to
be in the rackspace OEM any more.
fix(coreos-base/oem-vagrant): Use generic cloud config unit.
bump(coreos-base/coreos-cloudinit): relax deps in unit files
Merge pull request #547 from marineam/units2

Generic config drive