bump(coreos-base/vboot_reference): New cgpt version

Supports looking up disks via partition device nodes.
Merge pull request #408 from marineam/cgpt

bump(coreos-base/vboot_reference): New cgpt version
Merge pull request #409 from gregkh/systemd

bump(sys-apps/systemd) systemd is now version 211
bump(coreos-base/vboot_reference): small cgpt update
bump(coreos-base/cros-devutils): Various fixes for /usr images.
fix(sys-kernel/coreos-kernel): Install kernel image to /usr/boot

/boot is not included in /usr images
remove(coreos-base/coreos-installer): replaced by a small shell script

The tools this provided are moving to update_engine.
bump(coreos-base/update_engine): Support for /usr images
Merge pull request #410 from marineam/usr

Upgrade support for /usr