MFC r284269, r284270, r284655, r284656, r284658:
VHD fixes for Microsoft Azure:
- Round the image size to the VHD geometry and then round to a multiple of 1MB.
- Change the creator OS from "FBSD" to "Wi2k". It matters...
- Bump the VHD tool version and the mkimg version.
Approved by: re (gjb)