add(sys-firmware/edk2-ovmf): Add UEFI firmware for QEMU

To use either run qemu with:
  -bios efi-bios.bin
Or:
  -L path/to/usr/share/edk2-ovmf

The latter is useful if you want to use the OVMF built by the SDK
outside of the SDK. Using UEFI with the QEMU instance inside the CoreOS
SDK is kinda awkward because serial doesn't work and UEFI uses a VGA
graphics framebuffer mode, not VGA text mode so -curses doesn't work
either. In any case, it is a start.
fix(profiles): Unmask newer versions of SYSLINUX
bump(sys-firmware/edk2-ovmf): Update to new snapshot
bump(coreos-base/cros-devutils): Now includes chromeos-common.sh

This file was previously installed by the coreos-installer package.
fix(coreos-base/*): Clean up cros-installer and cros-factoryutils

cros-installer has already been removed, clean up lingering references.
cros-factoryutils installed nothing, just remove the ebuild.
Merge pull request #411 from marineam/syslinux

Syslinux and UEFI
wip, add nova-agent-watcher powered by cloudinit
Merge pull request #412 from marineam/quickfix

Fix cros-installer removal
feat(rackspace): update rackspace to use cloudinit
wip, add nova-agent-watcher powered by cloudinit
bump(): coreos-cloudinit and nova-agent-watcher
Merge branch 'rackspace' of https://github.com/polvi/coreos-overlay into rackspace

Conflicts:
	coreos-base/coreos-cloudinit/coreos-cloudinit-9999.ebuild
	coreos-base/nova-agent-watcher/nova-agent-watcher-9999.ebuild
	coreos-base/oem-rackspace/files/run
feat(cloudinit): add oem cloudinit unit
bump ebuild
Merge pull request #414 from polvi/add-oem-cloudinit

feat(cloudinit): add oem cloudinit unit
add(sys-boot/syslinux): Custom ebuild with better dependencies.

- Depend on util-linux
- Optionally depend on perl, don't install perl scripts when disabled.
fix(coreos-devel/sdk-depends): Install debinutils in SDK

The kernel's "make install" step requires /sbin/installkernel provided
by this package to work properly.
Merge pull request #416 from marineam/deps

Dep fixes
remove uneeded link
Merge pull request #413 from polvi/rackspace

feat(rackspace): update rackspace to use cloudinit