Implement a Windows installer using wimboot

This is implemented using the Windows 8 ADK and CD source; it presently works
to boot an image (named `razor-winpe.wim`) build by our client image
PowerShell script on the target machine.

Once there this has sufficient support to send a second stage PowerShell
script from the installer that will obtain the auto-install data, connect to
the specified SMB server, then fire up the Windows installer.

That uses an autoinstall XML file generated on the server, and manages
notification to the Razor server on completion and rebooting.  On first boot
the system should correctly proceed to process specialization and other
installer passes automatically with no further involvement from Razor.

Signed-off-by: Daniel Pittman <daniel@rimspace.net>