Merge pull request #825 from marineam/fix

update_engine: fix using delta_generator from update.zip
grub: add ebuild for latest snapshot of grub

Lots of bug fixing has gone in since beta2 was released in December.
vboot_reference: add grub bios partition type to cgpt
Merge pull request #828 from marineam/grub

grub: add ebuild for latest snapshot of grub
coreos-base/coreos-cloudinit: bump to v0.9.5
coreos-base/oem-digitalocean: Add DigitalOcean OEM